Add a compact room list option

This could be helpful if user have large amount of joined rooms, and it's also the default behavior of Element and other platform like Discord.

p.s. If compact room list was set, the "Option" button will be hide since it seems (I might be wrong so feel free to look into it) the button size is larger than the room item, which result the button is off-centered vertically. Since compact room list is somewhat "for PC" so I guess it's okay.