This should reflect what we actually support, while still being a superset
of what native drivers actually support.
Native driver support varies, but, as the comments document, native drivers
(at least as of windows 10) support only RGB -> RGB, YUV -> RGB, and BC -> RGB
conversions. The actual formats supported are a more limited subset than exposed
(despite that the video cards should be perfectly capable of supporting more
conversions) but erring on the side of overreporting seems safer.
--
v3: wined3d: Implement wined3d_check_device_format_conversion().
https://gitlab.winehq.org/wine/wine/-/merge_requests/5816