This issue is part of the course overview epic Phase 3.

According to the UX prototype, the forum activity has special actions to "subscribe all" and unsubscribe all".

 
Teacher experience prototype

Student experience prototype

To implement it, the activity plugin overview class must have a method to get the general action menu.

Technical note

At a technical level, adding an action menu is easy because the main action menu is a renderable element. However, capturing the events in JavaScript from the plugin could be challenging if we want to keep the course overview page independent from the plugin's code.