* WIP built-in resource packs API.
* Add built-in resource pack register API and fix old injection methods.
* Fix code style.
* Fix code style.
* Add documentation.
* Drop useless else.
* Fix resource packs and data packs isolation issues, and more.
* Move ResourcePackManagerAccessor to its own accessor mixin.
* Make the built-in mod pack test mod work on server too because data pack part.
* Add new argument to built-in pack method and make mod data packs always active.
* Add documentation.
* Complete documentation in GameOptions mixin.
* Remove register built-in pack overload as Player requested.
