0c10ada0cb
No functional changes intended. This adds `typedef`s for the enums used by Shape Keys. Doing so makes it clear what kind of values are stored under the `flag` and `type` fields. Also adding/cleaning-up comments that various functions in `key.cc` can be changed to a `switch/case`. In preparation for #136838 Pull Request: https://projects.blender.org/blender/blender/pulls/138595