Compile ahk2 project alongside main project

[mark-wiemer]

Progress on #453

• Move ahk2 submodule to root directory
• Update tsconfig to build ahk2 project alongside main project when running compile-ts
• Revert to Node 20 for stability
• Pin some types for compatibility with ahk2 project

[mark-wiemer]

blocking as manual tests aren't passing

[mark-wiemer]

Basic manual tests pass, extension is at least activating