Fix Clang-Cl compile on Windows

[06393993]

Introduce a MSVC_LIKE variable in the CMake scripts, set that variable to true only if the compiler is either MSVC or tries to emulate the MSVC command line, and test that variable when setting compiler arguments.

Tested with cmake .. -G Ninja -DCMAKE_C_COMPILER:PATH="clang-cl.exe" -DCMAKE_CXX_COMPILER:PATH="clang-cl.exe" -DFLATBUFFERS_BUILD_TESTS=OFF -DFLATBUFFERS_BUILD_CPP17=ON