Improve character animations

I can do this.

- [ ] More exciting walk/run sequences (head & body are perfectly still while limbs move)
- [ ] Blend between walk and attack
- [ ] Add more attack sequences?

## Versions & Hardware
- OpenDungeons-0.7.1-Linux64 & OpenDungeonsPlus-0.7.1 flatpak
- Linux Mint 22.1 Xia based on Ubuntu 24.04 noble based on trixie/sid
- Intel graphics, Intel(R) Core(TM) i5-6400 CPU @ 2.70GHz CPU