#15 `REQUEST_MERGE` project function
#15 Pushes the download button in the general command bar
#15 Refines the rights for download & upload
#15 Forcing the merge if needed
#15 Merge dialog for the message
#15 Applying the diff to the initial map (wip)
#15 Unit test for the diff applied to a map (wip)
#15 Unit test for the diff applied to a map (wip)