Undo/redo for animation/pose editing #32
Description
Right now you can undo while editing a pose, although it's not tied to whether you were editing a particular pose, if that makes sense, it's not scoped or whatever, and the situation is worse for editing an animation, where undoing is not tied to a frame. Undoing (and redoing) is not aware of the animation editing UI.
When you undo, it should probably switch to the relevant pose/frame if needed (and enter editing mode for an entity if needed), and it should avoid saving the world state, instead saving only the animation data while in animation editing mode.
It could be treated like the animation editing UI is a separate editor from the game world editor, with separate undo stacks, but I feel like it makes more sense to have them unified, because otherwise it would be unclear what scope you're undoing within (which editor), and because you could conceivably create an animation within the context of a world, in which case they would be semantically linked. For instance, you could animate a moving platform's path.