Development Widget: Create MR from linked Branch

Problem to solve

Users can create branches, or merge requests, from a work item. However if the branch is already linked, "Create merge request" does not support using that branch. In effect there is no way to create an MR for an existing branch from the work item itself (users can create MRs in numerous other ways).

This issue is focusing on the problem where a branch is already in the Development widget, and a user wants to now create an MR for that branch.

Proposal

• Add a "Create merge request" action within the branch actions menu
  • This should be the first item with a divider below.
  • This action should only appear to users who can create merge requests in the project where the branch exists.
• On click, open the new MR form with the branch selected and the "Closes <work item>" text inserted into the description.