* Move colorband and theme DNA to own headers
* Move some anim, curve, modifier and space enums to new headers
* Move data transfer enums to DNA
* Duplicate imbuf proxy and GPU backend enums
For a few reasons:
* Reduce number of includes in DNA headers
* Don't define enums used in DNA outside of DNA
* Move theme settings to separate header for userdef_default_theme.c
* Prepare for using default initializers in DNA headers. (#134531)
Pull Request: https://projects.blender.org/blender/blender/pulls/138831
f165c75e14