Only support GCC ARM compiler, but reap the benefits of static libraries instead of objects

CMake: Do not set `CMAKE_AR` ...

The variable for archiver is automatically set by CMake. There is
no need to explicitly set it, unless a project really needs to
override the default archiver.

Configure memory map per target to allow multiple add_executable

CMake: Refactor mapfile generation ...

The refactoring was necessary to remove a function call
(mbed_configure_app_target()) from application's CMakeLists.txt.

Fix some formatting issues.

Rebase linker script change properly, re-add external toolchain file support

Also update ARM.cmake

CMake ARM: move map to unify with Gcc Arm

CMake: Clean remnant of experiment with ARM toolchain ...

The removed code was testing that compiler flags could be added
to the assembler using generator expression. It was not to be
committed.

CMake: Set compile defintions for supported toolchain at top level input source file ...

The compile defintions should always be added depending on the
selected toolchain.
mbed_set_toolchain_options() should only be called if a third-party
toolchain file has not been used as it has compile options that can
cause conflicts.

CMake: Fix Microlib selection (#13871) ...

As the assembler does not seem to recognise the request to the
linker to use microlib, remove that instruction.
Microlib is still used as the linker selects microlib as a result
of being explicitly asked to do so.

Replace PUBLIC to INTERFACE keyword

CMake: Add a function to generate executable artifacts with memap (#13695) ...

- Add linker option to generate map file for GCC_ARM and ARM toolchain
- Add mbed_generate_map_file function to call memap.py (parse the map
file).
- Add mbed_generate_executable function to generate executable artifacts with a memory map table

CMake: Fix TFM targets build ...

Add linking time pre-processor macro DOMAIN_NS
for TFM targets and TrustZone non secure targets.

CMake: Add support for printf lib selection

CMake: Add support for C lib selection ...

Configure the selected toolchain for the selected C library

CMake: Move modules under tools subdirectory