Add Animation APIs

[ikeycode]

We need simple Animation APis for now that can be dirt simple (changing the texture).
These need some kind of timeline struct so that we can have multiple instances of an animation that aren't directly shared.

Animation API should step through Frames (potentially basic structs) and increment the index once per duration completion, with the ability to loop back to index 0. This will require an AnimationProcessor to step through all AnimationComponent instances for the sprites at the very least.

For Tile Maps we'll likely need a very specialised Animation class.