Add a Detect plagiarism button in the evaluation view

[BTWS2]

Teachers don't go very often to pages similar to https://dodona.be/en/courses/???/series/???/activities/???/submissions/.

In my opinion it makes sense to add Detect plagiarism button(s) in the evaluation view on pages similar to https://dodona.be/en/evaluations/???/ to make it more discoverable. Plagiarism checks makes most sense if the submissions are graded and students can earn points.

This is a quick mock-up what it could look like:

Detecting for plagiarism for a series in it's entirety would be even better, but Dolos doesn't support that.

[jorg-vr]

This was indeed the next step I had in mind.
This issue is related to #2503

Thanks for making the clear mockup

[pdawyndt]

The proposed solution only works for exercises that are part of an "evaluation". While this is a good place to launch plagiarism, we also need a discoverable place for exercises outside an "evaluation".