Aeolus/ICL: Build plan editor workflow enhancement

[b-fein]

Is your feature request related to a problem?

Currently, the Aeolus build plan has to be edited via the Programming exercise edit page.
Especially when iteratively working on the build plan and exercise setup, this becomes tedious since you need to navigate between at least three pages repeatedly (edit page, details page, repo).

Describe the solution you'd like

In Jenkins setups there already exists a special build plan edit page that has direct access to the solution/template build results. It would be nice if the Aeolus build plan could be edited from this page if the exercise uses Aeolus. I.e. the ‘Edit Build Plan’ button is visible for both Jenkins and Aeolus exercises, and the shown UI (text editor, or Aeolus steps editor) depends on which type of build plan editing is relevant for the concrete exercise.

Describe alternatives you've considered

No response

Additional context

No response

[b-fein]

Related: #8994