When we removed the nicescroll plugin from issues it causes some spacing issues that were added to make nicescroll play nice. This fixes that by fixing some of the padding that was causing the scroll area to be incorrect & the collapsed sidebar to have overflow issues

Closes #32357

Add test.js and test.css to disable animations during testing and include these in _head when testing

rerender scrollable-tab area after Resolve Discussions button is rendered

Add test.js and test.css to disable animations during testing and include these in _head when testing

change all .nav-links to use flex
place Resolve Discussions above tabs on small screens, and to the right on large

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/32125

Moved the data into the data method
Renamed edited ago class name

Removes the need for Bootstraps affix on browser that support sticky positions. On these browsers, there should be a slight performance improvement as there will be no scrolling events, it will all be handled by the browser