Refactor all usage of RegisterFunction to ScriptFunction::Register
- Replace ScriptInterface::RegisterFunction with ScriptFunction::Register
- Mostly removing unused cmpPrivate*
- Some usage introduces specific getters (mapgenerator, AIWorker, XmppClient,...)
- Several passthrough functions are simply removed in favour of calling the original, reducing duplication
- Make use of ScriptRequest/ScriptInterface capabilities where relevant.
- Make JSI_* headers only expose necessary functions, lightening them considerably and reducing duplication
- Reuse namespaces in JSI_* implementations directly, reducing visual noise there
Follows rP24969
Differential Revision: https://code.wildfiregames.com/D3626