Implement animator

Documentation: https://sdk.play.date/inside-playdate/#C-graphics.animator

P.S. I have example "animator" working. It requires `geometry`, `animator` and somewhat working `sprites` API. For sprites I used a bit modified work by @DomDomHaas (#45)

<img width="402" height="263" alt="Image" src="https://github.com/user-attachments/assets/c4dd6533-f58e-4980-b584-52e1b1367b23" />