Since the course refactor in Moodle 4.0 one of the requested features is to modify the activity or section action menu from the theme. However, that was not easy back then because each format can provide alternative outputs. This makes it impossible for themes to extend all specific control menu output classes.

Luckily, we now have PSR-14 hooks in the core, and the control menu can have a before hook to allow themes (or any other plugin) to manipulate the action menu items before rendering them.

This issue adds hooks to all three control menus (section, cm and delegated section).

The code must be based on MDL-83527 because this issue will refactor all course format action menus for Moodle 5.0.