[BUG] [UI] review submit box is cut off

[6543]

Gitea Version: 1.12.0+dev-142-g9b7737df2

[silverwind]

Another issue with that box I noticed that on small diffs (1 line), it will interfere with the page footer and extend below it. I think a proper fix is to use popper to position the box and give it a reasonable min-width.

[6543]

Closed by #11252