UI Changes to facilitate use on mobile Linux.

[YackyYam]

I have been trying to move to a Linux phone and being going app by app and got to music. Supersonic works well on mobile Linux, but there are some UI constraints that keep it from being usable. One being the window fitting into a phone screen. (See screen shot) The other thing that makes use difficult on a phone is scrolling. Having touch scrolling is a must rather than having to use the scroll bar. One awesome thing is music controls work from the lock screen. A few small changes would make this work greatly on a phone! I do plan on seeing what I can do to help this, but I'm not an amazing programmer.

A bit of info about the setup I'm using. I am using a OnePlus 6t flashed with PostmarketOS, a Linux distro dedicated for mobile devices with Phosh for the window manager that is based on GNOME. I think the changes I suggest would work for any device regardless of distro or window manager.

Edit: resized screen shots so they weren't enormous.
Edit2: Added info about my setup.