universalconquistador

Ports Blender 4.0 FBX anim export

1

This PR re-does the `fbx_animations_do` function by starting from the latest copy of the actual FBX exporter and then adding the changed bits I could identify. I'm not 100% sure...

Feature set registration was updated to use `DATA_PT_rigify` rather than `DATA_PT_rigify_buttons` in bb9469e3a41e578974deaa5d58dc49e05efdba94, but unregistration was not. This PR fixes that oversight. Can now unload and reload the gamerig feature...