Merge pull request #4186 from marpo60/fix_issue_4180_deletelabel_after_sprites

Fix icons-deletelabel styles
remove ["a", "b", "C"] from the void of nothingness [wtf]
Add back-to-top button on tag and user pages
Merge pull request #4191 from svbergerem/4185-BackToTop-other-streams

Add back-to-top button on tag and user pages
Add participants preview on conversations