Draft: Limit instructors list in all modules

What does this MR do?

Here I am limiting the number of instructors shown in every module to just 3 per time, and show the rest in a tooltip.

Task list ~"To Do"

• Show three instructors in dashboard
• Show three instructors in transcript
• Show three instructors in recent grades
• Show three instructors in registration-checkout
• Show three instructors in previous registrations

Edit: Returning and showing only courseClass instructors should be moved to the api.

Related issues and links

Fix #378

Other relevant links

Developer Checklist

• I have successfully run the code of this merge request locally

• I have verified locally that my changes work for all necessary screen sizes

• I have tried out the changes of this MR with different users to identify bugs

• Coding is in progress, and I have marked the MR as WIP

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Tech review Checklist

Have you verified that what is supposed to happen, actually does, and what is not supposed to happen, indeed does not?

• The MR accurately describes the changes and has a relevant title/description
• The MR does what it is supposed to according to its title, description and related issues/links
• I have successfully run the changes locally, and tried the new code

Overall review Checklist

• The MR references related issues/MRs
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• I have successfully run the changes locally, and tried the new code
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Closes #378