Auto-delete submissions matching Title or Username

**Is your feature request related to a problem? Please describe.**
I follow a lot of artists on FA and my submission queue can get very large if I don't keep on top of it. I use FurAffinity Extender to highlight submission notifications that contain "closed", "sold", or "reminder" for easy identification and it's wonderful for clearing out irrelevant notifications. But it would be even better if those were automatically cleared instead.

**Describe the solution you'd like**
I'd like an option that, when enabled, will do either of:
* Auto-delete any submission/journal notification that matches configurable text in my choice of Username or Title.
* Auto-delete any submission/journal notification that would be highlighted a specific color by the existing text-matching system. (for example, I could set "ORANGE" highlight to auto-delete, and then I could configure the auto-delete by setting terms to highlight in "ORANGE".

**Describe alternatives you've considered**
I've considered forking faextender and trying to add this myself, but I'm only an amateur programmer and this would be my first foray into browser addons. I'm not sure I'm capable and I'd be very slow at it.
I'd also accept an addon that lets you purge submissions with specific text or usernames from my entire notifications queue at once.