UI for adding Public Share Rooms

Added a new UI for adding public share rooms and changed add button to be in the nav / action bar.

I also updated the "X" button for removing a public share room, but I am not sure that's how it should be done. I am thinking it should probably be a long press pop up on android and a swipe that reveals a delete button on ios,

This is OK for the moment while we solidify some of these UI concepts.

//cc @kenmanheimer