Closes #50405

Fix #47913 (again), revert !21180, fix regression of !8652, improve !20137

This isn't interesting most of the time and is may go over other flash banners.

These don't have performance data saved as they use Grape.

Filipa Lacerda authored 6 years ago and Jose Ivan Vargas Lopez committed 6 years ago

When backend sends HTML it requires frontend to append it to the DOM causing
XSS vulnerabilities. By removing the `<br>` we avoid those vulnerabilities

Also:
- Increased presence of 'commits behind' text
- Added link to target branch in 'commits behind' text

Also:
- Renamed .label-truncated to .label-truncate
- Removed length checking in JS to let the CSS handle this
- Improve IE11 compatibility of MR headers

#47947

Regenerate pot files

Remove `#`

Remove empty lines

Closes #50255

Closes #48059