Option to not use `-march=native` for compatibility

[nyurik]

Current cmake files use -march=native unconditionally:

FastPFOR/CMakeLists.txt

Lines 90 to 96 in aa1a6c3

	unset(FASTPFOR_COMPILER_SUPPORTS_MARCH_NATIVE CACHE)
	CHECK_CXX_COMPILER_FLAG(-march=native FASTPFOR_COMPILER_SUPPORTS_MARCH_NATIVE)
	if(FASTPFOR_COMPILER_SUPPORTS_MARCH_NATIVE)
	target_compile_options(FastPFOR PRIVATE -march=native)
	else()
	message(STATUS "native target not supported")
	endif()

This breaks for many usecases - e.g. when the library is being distributed as a binary. Moreover, it even breaks the GitHub CI builds because there are two types of x64 runners - Intel and AMD, and the later one does not support AVX instruction set. So if a build cache is being used, the build fails - see maplibre/maplibre-tile-spec#1016

Ideally, it should be possible to have a single binary capable of using the right instruction set at the runtime - i.e. dynamic dispatch. There could be a cmake flag with modes like native|compatible|dynamic -- which would produce either the binary for the current CPU, a binary with maximum compatibility to the older CPUs, or the binary that can autodetect CPU instruction set.