CMake: Add test for multiple-executable support ...

Add a test to build two executables in two directories under a single
project.

Rework post-build to support multiple executables ...

When building greentea tests, each test is an executable with its
own output binary path. This is also the case when a user project
produces multiple executables. But the current implementation of
post-build operations always assumes there's only one executable,
at the root of the build directory.

The post-build command depends on Mbed target, and it always takes
the the executable we build as an input file. To achieve this, we
let each Mbed target (that has a post-build command) define a function

    function(mbed_post_build_function target)

which takes a CMake executable target as an argument from which it can
get its binary path using generator expressions. It generates and adds
to the passed executable target a post-build custom command.

Notes:
* The function name needs to be exact, because CMake only supports
literal function calls - CMake can't dereference a function name from
a variable. To avoid multiple definitions of this function, each Mbed
target needs to guard it with a macro to check if the user is
building this Mbed target.
* `mbed_post_build_function()` is a function, but it is usually
defined by another macro rather than a parent function, because
nesting functions would make many variables inaccessible inside the
innermost `mbed_post_build_function()`.
* There's no more need to force regenerate images. Previously, post-
build commands were custom *targets* which always got to run, so we
force regenerated images on every build to avoid patching an image
that's already been patched once on previous build. Now post-build
commands are custom *commands* of the same executable target, and they
are only run if the executable target itself is rebuilt.

CMake: Move post build functions out of root CMakeLists.txt ...

The 'post build' functions are made visible by adding the mbed-os
subdirectory. This is not ideal as any components in mbed-os wishing to
call the functions must be added after the functions are defined. To
improve modularity move these functions to a separate CMake script.

We include the post build CMake script in app.cmake for now so we don't
break user's projects.

Merge pull request #14940 from Patater/update-prettytable ...

python: Allow newer prettytable with newer python

python: Allow newer prettytable with newer python ...

This helps to allow installation of Mbed OS's Python requirements, when
CMake is used, into the same Python environment as mbed-os-tools. The
versions specified here are aligned with mbed-os-tools;
tools/cmake/requirements.txt depends on the same version of prettytable
as mbed-os-tools's requirements.txt.

Merge pull request #14932 from ARMmbed/remove_tools_host_tests ...

Remove host_tests from mbed-os/tools

Merge pull request #14880 from Patater/dont-require-icetea ...

Dont require icetea

Remove host_tests from mbed-os/tools ...

host tests (mbedhtrun) is maintained as part of mbed-os-tools but there
is a redundant duplicate of host_tests under mbed-os/tools/ directory
this PR changes to remove those duplicates and update test_api py modules
to use host tests from mbed-host-tests

icetea: Remove icetea TEST_APPS ...

icetea was intended to be deprecated in Mbed 6. icetea is no longer
maintained. Remove icetea-specific TEST_APPS and run_icetea tests from
Mbed OS.

CMake: greentea: Fix io issue with greentea-client ...

The stdio implementation of the standalone greentea-client wasn't
streaming "KiVi protocol" messages through the serial IO. Separate out
the existing implementation for greentea-client that uses
mbed_retarget.h's `read` and `write` functions so greentea tests
continue to work with the standalone client.

The IO fixture is shared between the "legacy" embedded greentea-client
and the newer standalone client.

Merge pull request #14872 from hallard/STM32WLEx ...

Add STM32WLE5 for custom targets LORA_E5 and RAK3172

cmake: Use namespaced greentea client library ...

When using an exported or installed version of greentea, it's necessary
to use the greentea namespace.

Use standalone greentea-client ...

For CMake or Mbed CLI 2, use the standalone greentea-client.

added STM32WLE5CCUx + version 1.1.0

CMake: Replace MBED_TEST_LINK_LIBRARIES with MBED_TEST_BAREMETAL ...

Currently we have `MBED_TEST_LINK_LIBRARIES` for specifying
* Whether to link `mbed-os` or `mbed-baremetal`
* Any additional libraries we want tests to link

It's not fit for purpose anymore, because
* No flavor of Mbed OS is selected by default, but we should've
really defaulted to `mbed-os`, the full RTOS version. Build doesn't
work unless `-DMBED_TEST_LINK_LIBRARIES=<...>` is passed, which
is redundant.
* A test should never need additional libraries passed via command
line - its `CMakeLists.txt` should specify what it links.

This commit replaces `MBED_TEST_LINK_LIBRARIES` with a new option
`MBED_TEST_BAREMETAL` to build a test with either RTOS (default)
or without it (by passing `-DMBED_TEST_BAREMETAL=ON`).

app.cmake: Replace tabs with spaces ...

The coding standards of Mbed OS require indentation of four spaces.

Merge pull request #14783 from rwalton-arm/dont_capture_stdout ...

tfm-post-build: Don't capture subprocess stdout

Merge pull request #14876 from rwalton-arm/mbed_path_greentea ...

CMake: greentea: Remove dependency on global MBED_PATH

CMake: greentea: Remove dependency on global MBED_PATH ...

The mbed_greentea_add_test macro required a greentea test to set an
MBED_PATH variable to the path of the mbed-os root directory, which it
attempts to add as a 'subdirectory' of the test project. We can instead
use CMake's built in CMAKE_CURRENT_LIST_DIR variable to deduce the path
to mbed-os relative to the current list file directory, removing the
need for greentea tests to set MBED_PATH.

CMake: greentea: Remove call to deprecated function ...

mbed_greentea::mbed_greentea_add_test was calling the deprecated
`mbed_configure_app_target` function, which is currently a no-op.

enable google and azure example application tests in ci

added STM32WLE5JCIx

CMake: mbed_greentea: Remove trailing whitespace

Merge pull request #14718 from Meano/develop ...

Feature: Make changes for Cortex-A5 support

Merge pull request #14780 from Patater/update-python-requirements ...

Update python requirements

Merge pull request #14815 from LDong-Arm/test_psa_k64f_k66f ...

Enable PSA tests on K64F/K66F and fix missing PSA Crypto init in TLSSocketWrapper

python: Update requirements ...

Update versions of urllib3, PyYAML, jinja2, cryptography.

tfm-post-build: Don't capture subprocess stdout ...

subprocess.PIPE is used to enable the parent process to communicate with
the subprocess via pipes, which mean all stdout and stderr messages are
captured and returned as part of Popen.communicate's result tuple.

In our case, we want to display the error messages on the console, so we
don't need to capture the output from stdout.

Example of a typical error message before this change:
```
Traceback (most recent call last):
  File "platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/scripts/generate_mbed_image.py", line 197, in <module>
    sign_and_merge_tfm_bin(args.tfm_target, args.target_path, args.non_secure_bin, args.secure_bin)
  File "platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/scripts/generate_mbed_image.py", line 81, in sign_and_merge_tfm_bin
    " secure binary, Error code: " + str(retcode))
Exception: Unable to sign musca_b1 secure binary, Error code: 1
```

Example of the error message after this change:
```
Traceback (most recent call last):
  File "/mbed-os/tools/psa/tfm/bin_utils/wrapper.py", line 13, in <module>
    import click
ModuleNotFoundError: No module named 'click'
Traceback (most recent call last):
  File "platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/scripts/generate_mbed_image.py", line 194, in <module>
    sign_and_merge_tfm_bin(args.tfm_target, args.target_path, args.non_secure_bin, args.secure_bin)
  File "platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/scripts/generate_mbed_image.py", line 80, in sign_and_merge_tfm_bin
    raise Exception("Unable to sign " + target_name +
Exception: Unable to sign musca_b1 secure binary, Error code: 1
```

This is a significant improvement as now you can see what the reason for
the failure was.

CMake: Require TEST_SOURCES in greentea CMake file ...

Assumption that greentea test file is always named main.cpp is
incorrect. Updated mbed_greentea_add_test() macro to make TEST_SOURCES
parameter compulsory, which is used to specify greentea test
file(s). This allows tests to use C, or have a different name.
Therefore also updated all pre-existing greentea test CMake files to
explicity add main.cpp to TEST_SOURCES.

CMake: Remove alias for TEST_NAME argument ...

The mbed_greentea_add_test macro previously set a variable in order to
use the un-prefixed TEST_NAME to refer to the argument in the macro
body. Whilst pair-programming with LDong, this was identified and
determined to be unecessary (maybe it was a failed attempt to fix
something, that was never reversed?) and so it has been removed.