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

Convert storage/ targets into STATIC libraries

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

CMake: QSPIFBlockDevice: Guard unit test directory ...

In the QSPIFBlockDevice component we checked if BUILD_TESTING was
enabled before adding the QSPIFBlockDevice/UNITTESTS subdirectory. In
the parent blockdevice/CMakeLists.txt we added the QSPIFBlockDevice
subdirectory to the build under two separate conditions:

* when "QSPIF" is present in MBED_TARGET_LABELS
* when building only unit tests

This wasn't quite enough, as when we build greentea tests for some
targets QSPIF is enabled in MBED_TARGET_LABELS, causing the
QSPIFBlockDevice subdirectory and its unit tests to be added when
building greentea tests. This caused a test failure on targets which
enable QSPIF:

```
The following tests FAILED:
	 40 - qspif-unittest_NOT_BUILT (Not Run)
```

To fix this we need to specifically check that we're not building
greentea tests before adding the QSPIFBlockDevice/UNITTESTS directory to
the project.

Part of this issue is our reliance on MBED_TARGET_LABELS to pull
features in to the build. We should refactor our usage of
MBED_TARGET_LABELS and use CMake target dependencies where possible.
Then we wouldn't need to add subdirectories under various, often
conflicting, scenarios. Instead the targets would always be available
and we would just choose which ones to actually build in different cases
using CMake target linking.

QSPIFBlockDevice: Add unit test for the S25FS512S quirk ...

Add a test case to verify that the quirk on `CR1NV` and `CR3NV`
registers get applied by `QSPIFBlockDevice` when the flash device
is S25FS512S.

`QSPIFBlockDevice` depends on the SFDP functions and the `QSPI` class,
but we can't use gMock on them because:
* SFDP functions are global functions, whereas gMock only supports
mocking class member functions.
* A mocked class is injected into the test subject, but passing a
preexisting `QSPI` instance into `QSPIFBlockDevice` is not possible
(unless we resort to pointers). For details, see comments in
test_QSPIFBlockDevice.cpp.

So fakes of the `QSPI` class and any SFDP functions involved are
defined in test_QSPIFBlockDevice.cpp.

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 blockdevice components source and include paths ...

This file paths were updated on master and this was broken after
rebasing.

CMake: Fix failures due to device_key and storage dirs move

CMake: Add support for storage dir