We can define return types using `function(): TYPE` notation.
We should do that when it's possible.
For now, it's not possible to type nullable return type (PHP7.1
supports that, but PHP7.0 and most probably HVVM doesn't),
Change-Id: I6b58a882383832313ef47a296c726a4044a97954
Changes:
- moved all menu elements definitions from SkinMinerva into
a separate Definitions.php file
- moved menu building from SkinMinerva into includes/menu/Main
folder
- introduced Builder pattern for easy menu building
Minerva/Menu/Main/Director takes an Minerva/Menu/Main/IBuilder
and builds the menu. The IBuilders use definitions from
Minerva/Menu/Definitions file, so all definitions can be shared
across different menus
- used ServiceWiring file to register MainMenu Director as Service
- left class_alias for old MenuBuilder as some extensions still use it
- The hooks system have to stay like that as some extensions
are using it (BlueSpiceMultiUpload and GrowthExperiments).
- introduced AdvancedMenu builder for the AMC mode
Bug: T216152
Change-Id: I210c3f1fa36bbd2f9108d728b12cbb21ee210354
