Implement UI for new MR page

mentioned in issue #3043 (closed)

Added ~121287 label

Milestone changed to 8.4

Added frontend and removed ~121287 labels

@creamzy is this outdated?

Right now UI is almost the same, but some minor things need extra tuning, like background under the button, avatar size

@JobV I will mockup also message and maybe other state

Milestone removed

Also for possible messages

we can shot something like "Can’t automatically merge" or "Can be merged automatically", or "There isn't anything to merge." or error, for example when a merge request for these branches already exists.

Added ~19492 label

Milestone changed to 8.5

@creamzy sounds good!

Removed ~19492 label

Reassigned to @iamphill

Milestone changed to 8.6

mentioned in merge request !3228 (merged)

Milestone changed to 8.7

mentioned in commit c5c05f6a

Status changed to closed by commit c5c05f6a

mentioned in commit 69a8bf36