fixes#11334
use shiftstates consistently;
map shiftstates to mac shiftstates(mac, rgkey, win);
remove unneccessary functions;
rename functions to have more systematic
consolidate order of parameters in functions;
rename variables (casing), and also to clarify shiftstates;
handle unused positions in USVirtualKeyToScanCode+ScanCodeToUSVirtualKey;
use util_filesystem.cpp/h from Keyman instead of my own filesystem.cpp/h;
remove deadkey.cpp/h;
feat(mac): mcompile new X_find_Shiftstates to verify shiftstates
feat(mac): mcompile fill rgkey for base, shift, opt, shift+opt including CAPS
feat(mac): mcompile fill rgkey prevent writing x01 into rgkey[]
feat(mac): mcompile tidy up code
feat(mac): open more functions
feat(mac): open DoConvert-InitializeUCHR
feat(mac): open write_US_ToVector
feat(mac): (temporarily) add mac_ to function names to be able to distinguish between linux-functions and mac functions if needed
feat(mac): finished mac_createOneVectorFromBothKeyboards()
feat(mac): started DoConvert
feat(mac): mcompile tidy up
feat(mac): include km_types and u16
feat(mac): include filesystem and some kmx
feat(mac): include old functions in keymap
feat(mac): include kmx_file, mc_kmxfile
feat(mac): include deadkey, filesystem, km_types, import_rules,mc_kmxfile
feat(mac): include functions in mcompile.cpp/h
feat(mac): #includes out to be used
