Untangles dependencies by splitting up `engine.{h,cpp}` into 3 files:
1. `primitive_render`
2. `ticks` -- only contains `GetAnimationFrame` for now.
3. `GetWidth2` renamed to `CalculateSpriteTileCenterX` and moved to `levels/dun_tile.hpp`.
Identified and removed an instance of Direction being used as an argument for a bool parameter
Removed a single-use temporary variable being cast from sprite frame to direction to size_t
Co-authored-by: Anders Jenbo <anders@jenbo.dk>
Fix alignment of WalkSettings array