Make download submission for tutors functionality accessible from multiple places

[florian-glombik]

Is your feature request related to a problem?

When monitoring student progress for programming exercises teaching assistants often clone the student submission and run the tests locally to identify and resolve issues.

Describe the solution you'd like

With #56 Orion offers the functionality to download student submissions, integrated into a test project setup.
It would be great if this functionality can be accessed from multiple places in Artemis.

I found the following places that would be beneficial to be supported:

• Participation view
  Often used when students report problems with the exercise/tests and a teaching assistant
  
• Scores view
  
• Assessment Dashboard Submission view
  

Describe alternatives you've considered

The teaching assistants can also do this manually, but this takes time that should rather be spent on resolving issues.

[MDK5]

While I don't think it makes too much sense to add the buttons on the participation and scores page since Artemis does not offer a link to the assessment there either, the table in the submission page could be adapted to behave like the table in the assessment dashboard - showing a button to open the exercise when its not open and offering to download the assessment when the right project is opened