This is a slight refactoring of the Win32 IME code to remove the use of
Language IDs, which is now strongly deprecated. Instead this uses the
new recommended Locale Names, ie ISO-639-1 2-letter abbreviated names
like "en" for English rather than ID 0x09.
See D12143 for more details.
Differential Revision: https://developer.blender.org/D12143
Reviewed by Ray Molenkamp
946da86e02