Refactor the keyframe copy-paste code to prepare for supporting action slots.
This is a non-functional change, as the slots are stored but otherwise completely ignored. This way the refactor to the new data structure can be reviewed & tested before actually changing the behaviour.
Related: #129690
Pull Request: https://projects.blender.org/blender/blender/pulls/133497
Simplify `pastebuf_match_path_property()` by reducing cognitive complexity
and using `StringRef::endswith()` instead of pointer arithmetic.
I've also added a few unit test cases that cover some unwanted behavior:
the property name check only checks suffixes, and so copying "….location"
will also paste it to a "….not_actually_location" F-Curve.
No functional changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/133005
Add a unit test for the bone name flipping function of the keyframe
paste functionality.
The function itself has been changed a little bit, so that it returns a
`std::string` instead of using a `char **` return parameter that needs
explicit freeing at the call site. This made the tests considerably
simpler to write. This change does cause an extra copy of the RNA path,
but that should be refactored away soon.
No functional changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/133005
