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`.
Fully migrates debug commands to Lua and organizes them into logical
groups.
The CLI `+` syntax now runs Lua, e.g.:
```bash
build/devilutionx '+dev.player.trn.plr("infra")'
```
Chat hotkeys run Lua code if they start with `/lua`, e.g.:
```ini
[NetMsg]
QuickMessage1=/lua message(dev.player.info())
```
Gleb Mazovetskiy
staphen