[Saving]: Implement Save/Load for `Actor`

[zCubed3]

Goals

• - [Saving]: Implement Save/Load for ObjectFrame #8
• - [Saving]: Implement Save/Load for FrameGroup #9
• - Implement Save/Load for ActionFrame (if possible)
• - Prototype Saving and Loading - Implemented in c614102
• - Add UI entries for saving and loading individual takes
• - Allow saving an avatar take to an MDAT file
• - Spawning avatar from Barcode stored inside MDAT files
• - Freeze file structure for MDAT V1