Rename inconsistently named testing-related variables. Also fix STM32CUBE not working from application code.

Convert lorawan to a STATIC library

Convert emac, cellular, and wifi targets, and enable one UDP test

Convert the rest of the hal tests, convert mbedtls to an OBJECT library

Clean up top-level build file and build options, fix build issues on MinGW

CMake: connectivity: Guard unit test directories ...

When unit tests or unit test stubs get added as CMake targets, they
becomes part of the "all" target and get compiled when building the
whole project. When building greentea tests we need to disable unit
tests and stubs to avoid unnecessary compilation and errors.

CMake: Move mbedtls stubs to the mbedtls dir ...

Move the connectivity mbedtls stubs into the connectivity/mbedtls
component directory. So we can avoid duplicating the mbed-os source
tree in a central UNITTESTS folder.

mbedtls: Rename Mbed timing implementation ...

We get a linker warning with the recently added timing module
implementation for Mbed. This is because there is Mbed TLS also ships a
file called timing.c, which we are including in Mbed OS also. With CLI
1, we get an error about unique object files because of the similarly
named implementation files.

    Object file timing.o is not unique! It could be made from: mbed-os/connectivity/mbedtls/source/timing.c mbed-os/connectivity/mbedtls/platform/src/timing.cpp

Rename the Mbed timing module implementation to timing_mbed.cpp to avoid
this naming conflict.

Fixes: b8781e527bc1 ("mbedtls: Add an alt implementation of timing")

Fixes #14759

mbedtls: Add an alt implementation of timing ...

Implement the MBEDTLS_TIMING_ALT interface for Mbed OS. This
implementation is sufficient to run the Mbed TLS benchmarking
application.

tls: Upgrade to Mbed TLS v2.25.0

CMake: Fix Mbed TLS compilation for Cortex-M0/0+/1/M23 ...

Due to a known issue in Mbed TLS's architecture determination
(ARMmbed/mbedtls#1077), we get the error

    error: inline assembly requires more registers than available

when compiling `bignum.c` for Cortex-M0/0+/1/M23 which do not have
the macro `__thumb2__` set by the compiler.

The workaround is to define the macro `MULADDC_CANNOT_USE_R7` which
is already defined by Mbed CLI 1 but missing in our CMake support.

Fixes ARMmbed/mbed-os-example-lorawan#220

Move hash_wrappers.c to platform subdirectory ...

hash_wrappers.c is specific to Mbed OS, moving it into platform
as its original directory is for imported Mbed TLS source only.

CMake: Rename CMake targets ...

* mbed-os renamed mbed-core
* mbed-os-<COMPONENT> renamed mbed-<COMPONENT>

CMake: Componentize Mbed OS into multiple CMake targets (#13732) ...

Aside from the core mbed-os CMake target, a number of targets have been created so they can optionally be included by application executables that require them using `target_link_libraries()`.

Co-authored-by: Martin Kojtal <martin.kojtal@arm.com>
Co-authored-by: Rajkumar Kanagaraj <rajkumar.kanagaraj@arm.com>

CMake: Fix failure due to MbedTLS rdir relocation