Course editor: Migrate hide, show and make available course tools to the new reactive actions.

Since Moodle 4.0 the course editor frontend part uses two main modules to handle the edition tools:

• core_course/actions: responsible for handling all non-reactive tools and the legacy formats
• core_courseformat/courseeditor: the new reactive library that updates the course index and the course content

Since the reactive implementation starts, the final goal is to replace all legacy actions with the new ones as soon as possible. The most complex ones like moving elements, deleting, and creating sections are already migrated and others like indent are just deprecated (or leave it to third-party plugins).

In this issue the visibility tools will be migrated to the new module:

• Hide section/activity
• Show section/activity
• Make activity available