Fixes hidden scrollbar.

fixes #4194
- Remove relative positioning
Merge pull request #4195 from halfdan/4194-scroll

Fixes hidden scrollbar.
Allow scroll on setup form
Fix notifications being cur off on auth/setup screens
Prevent horizontal scrolling in the PSM
Merge pull request #4197 from PaulAdamDavis/minor-052-bugs

[WIP] Fix minor styling bugs
Remove sliding animation between content & list & post preview on mobile
Make the PSM tabs transition only happen on desktop