Display when a merge request was merged near the title

Problem to solve

After a merge request has been merged, the information when is was merged is more important than when it was opened. However that information is only visible when scrolling down (depending on screen size and length of merge request description).

Proposal

There are a few things that we can do:

• add tooltip with date to merged badge:

• add another line to the merge request header:

• collapse long merge request descriptions with a read more button after merging

• move the information about opening the merge request to the merge request widget (not sure what about the tasks)