Implement Displaying All Users on Explore Tab

[GarvinYoung]

Acceptance Criteria:

• [ ] implement 2 subtabs on the explore tab
• [ ] the first tab is titled study groups and is what is already displayed ont he explore tab
• [ ] the second tab will display all the users, similar to how friends, following, and followers are implemented
• [ ] dont include yourself
• [ ] there will be a search bar where you can search user by username