Compact GUI/ Channel Specific Player Args

[moswald14]

Checklist

• I understand that Streamlink Twitch GUI is just a launcher for Streamlink
• I have read the contribution guidelines
• I have checked the list of open and recently closed issues
• I have checked the commit log of the master branch

Description

Here's 2 suggestions in one:
I really like the gui, but it could use some improvements. one thing I would like to see is a "compact gui" where it could just show followed channels that are live and a button to get to the menu or restore the full gui. Basically, I want the sidebar that is on twitch.tv. the ability to keep the window on top and/or auto hide and show with mouseover like the windows taskbar can would be cool as well. more customization options would be awesome as well, like icon size, orientation, and maybe a grid layout.

another idea I have is channel specific player args. I watch a streamer who puts their volume at about double what all other streamers do, so I want to pass an arg that sets the volume to 50% just for this streamer. you could have the option to replace args as a whole or append the current player args.