* Fix: removed d3d12_lib from main meson.build, so it could be builded on linux
* Fix: better d3d12_lib OS check
* Fix: remove abundant d3d12 checks from tests meson.build files
1. Googletests subdir was added. This requires GTest to be installed. If it is not installed, it's skipped
2. Moved some local variables to the main file to prevent duplicate library_finds and problems that can occur with local calculations.
1. Minor fix - add URL to pkg-config file
2. When building tests, make dxcore optional if not using "msvc"
3. programs in test directory now build even on Windows.
4. Compile DirectX-Headers-Check-Feature-Support-Test.exe if tests are on
5. Use test() statements to add DirectX-Headers-Test.exe and DirectX-Headers-Check-Feature-Support-Test.exe to "test" build target (typically invoked with something like "ninja test" or "make test".
DirectX headers is now a static library instead of just an interface. It will compile `d3dx12_property_format_table.cpp`
- Updated CMakeLists.txt
- Updated Meson.build
