Feature request: filter tray icons to group different icons in different parts of the bar

[redpenguinyt]

I want to use nm-applet as my wifi indicator with its context menu and all, however I don't want it to sit next to my other tray items (Discord, etc.). It would be nice to be able to set some tray items to not appear in a tray (something like an exclude/include selector)

[Fxxxlei]

I would like to use this kind of thing for a few things as well, as it would allow me to group nm-applet with connectivity indicators, fcitx (or other IME) with keyboard indicators, group messengers together...

[fxzzi]

I like this idea, if we were to get this it could also work as a way to exclude certain applets in tray

[AlexChalk]

➕1, it would be neat to have block/allow functionality for the tray.