[Feature Request] Priority system for media keys

[JoeJoeTV]

 * csd version: 5.6.1
 * Distribution - Mint Cinnamon 21.1
 * NVIDIA GTX 1060 6G, nvidia proprietary driver
 * 64 bit

Issue
I think it would be really nice, if one could prioritize applications for media key grabbing, since every time I open my web browser(chromium based) after my music player application, the web browser gets the media key focus, but I want my music player to have the focus.
A solution, would be to disable this for the browser, but the problem is, that I sometimes actually want to use them in the browser.
I propose a setting or similar, where you can either add programs, that don't get their media key focus taken away, if another tries to grab them or a system, where you can set priorities per program, so that the one with the higher priority gets chosen over other ones with lower priorities.
A feature to disallow certain applications from getting the media key focus would also be nice, either a whitelist or a blacklist.

Steps to reproduce

1. Open Music Player
2. Open Web Browser
3. Media Keys control Web Browser instead of music player

Expected behaviour
To be able to have more control over how the media keys work

Other information

[rcalixte]

@JoeJoeTV This works for me if I select the sound source in the Sound applet. There is a "Choose player controls" option that should allow you to select between multiple MPRIS clients. (I have a similar use case myself. 😅)

You can also set key bindings in the applet settings to show the menu so that you can see which application is the current default MPRIS client.

[JoeJoeTV]

Hi, I know of that option and I also use that, but that doesn't help with the Media Keys sadly. My workaround would have been to use playerctrl with rebound play/pause/skip/etc keys, but playerctrl has a problem with one MPRIS application I use, so I can't use that right now.