Profile and group refactor

This includes all **client side** changes necessary for the implementation of user profiles and improved study session descriptions. A summary of changes is as follows:

1. Added year of study, level of study, program and about me fields to user profiles. Most of these (aside from about me) are set during account creation. They can all be edited in the Edit Profile modal
2. Added the ability to view user profiles by clicking names on session cards. This may not be the most meaningful way of doing this, and I decided against adding them to the bubbles for space reasons, but we can talk about improvements if need be.
3. Added participant cap and description fields to study sessions. When a study session is full, it will be hidden from the (newly renamed) Find Sessions tab. It will still show up if necessary in the Hosting/Attending tabs. Description will also show up in the bubble for each session.

**Please, please, please test this thoroughly before accepting. I've run fairly rigorous manual test cases on it, but the more people we can have verifying it, the better. Also, if you have any questions/comments/concerns, please leave them as comments on this pull request and I'll address them ASAP.**