Programming Exercise: Add Exercise-Wide Online IDE Settings

[iyannsch]

Is your feature request related to a problem?

The currently existing online code editor in Artemis is a great tool for beginners to jump into programming exercises. However, its functionality is limited for more advanced use cases. In my master's thesis, we implement the online IDE Theia as an alternative way to interact with the Artemis exercise workflow. Student do not have to set up an IDE locally anymore, saving them time and the struggle to configure it to fit their numerous courses. Currently, instructors cannot define whether they want students to have access to an online IDE for a specific exercise.

Describe the solution you'd like

Add available IDE images to a config file so that we can define which versions of Theia are available.

Add a server endpoint to provide the client with all available images including their purpose or name.

Show instructor options to en-/disable the online IDE for an exercise and configure it if available.

Describe alternatives you've considered

Additional context

This is a sub-issue of the feature proposed in #8602