Mobile side drawer

Replaces panel switching altogether:

• Adds a new menu button on nav bar on mobile, removes all the small icons
• Adds a side drawer that opens from the menu button, side drawer contains all navigation links
• Adds chat back to mobile (very unrefined when it comes to the styles
• Adds search field to user search route, so the user search input box isn't necessary in nav bar
• For now removes the nav bar back button too