Messaging View Overhaul

This is the biggest push to date in terms of changes.
The PR addresses 7 issues in the workflow panel:

1. It fixes the conversation height issue, scrolling stops working bug on load
2. Conversation area height is also enlarged
3. It dynamically displays user initials in the conversation area
4. The options panel are hidden on mobile (mobile is conversation only)
5. Back home button has a slightly better styling
6. The conversation shapes are dynamically generated based on the number of participants and their colors

Check them out guys @psybuzz @nikilselvam !
It may be best to keep `.display-fade` and `.display-fade-bottom` on the same line here, as we seem to do with other blocks of SASS in this file that contain multiple selectors for consistency's sake