No functional changes.
This PR just replaces the `KEYFRAME_OK_CHECKS` macro with a function
`keyframe_ok_checks`.
The motivation for this is to remove the confusing use of nested macros.
Since the actual check has to be passed in, this new function takes a function as an argument.
Pull Request: https://projects.blender.org/blender/blender/pulls/118914
c28e1bb482