Chore: Move Blender client code

[iLLiCiTiT]

Changelog Description

Moved blender client code next to server codebase.

Additional information

Renamed base plugin classes to contain Blender prefix. Added base classes for blender instance and context pyblish plugins having settings_category.

Notes

Discovered that workfile create plugin inherits from both AutoCreator and Creator, which should not happen.

Testing notes:

1. Create package of blender and core.
2. Upload both to server.
3. Make sure AYON launcher is using client code from this PR (e.g using dev paths).
4. Blender integration should work as before.

[ynbot]

Task linked: AY-5650 Move Blender client code

[moonyuet]

Tested successfully in blender.__