cmake : MSVC instruction detection (fixed up #809) (#3923)

* Add detection code for avx

* Only check hardware when option is ON

* Modify per code review sugguestions

* Build locally will detect CPU

* Fixes CMake style to use lowercase like everywhere else

* cleanup

* fix merge

* linux/gcc version for testing

* msvc combines avx2 and fma into /arch:AVX2 so check for both

* cleanup

* msvc only version

* style

* Update FindSIMD.cmake

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Co-authored-by: Howard Su <howard0su@gmail.com>
Co-authored-by: Jeremy Dunn <jeremydunn123@gmail.com>