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())
```
Scrolling: PageUp/Down and mouse wheel.
History navigation:
* Up/Down navigates the input history.
* Shift+Up/Down navigates the output history (allowing us to copy/paste the
outputs, I imagine this will be very handy).
* Duplicates are skipped.
Enabled only in Debug mode.
Runs Lua similar to the `lua` CLI.
Supports multiline input with Shift+Enter.
Missing features:
1. Scrollback.
2. Input history on up/down.
Open with backtick, close with Esc.
Gleb Mazovetskiy