Plugin Request - Sorting Channels like Discord Servers into Folders

**Is your feature request related to a problem? Please describe.**
I'm often overwhelmed by the chatter of many IRC channels. It would be nice if I could chuck a bunch of high-volume channels into a folder (like ##ubuntu/##Linux/etc) into a single folder and make rules for notifications (name ping only).

On the flip side, there are teensy tiny channels with a handful of users, and I'd like to never miss any messages there, I'd like to keep those separate from folders or perhaps lump them into a "super notification" folder.

**Describe the solution you'd like**

Folders/Tags for channels that allow for increased configurability of notifications and additionally to visually declutter a busy channel list.

**Describe alternatives you've considered**

I've seen this with some GUI clients, but I can't recall which. Additionally, I'm not sure if I've seen such a function in a web client before.

**Additional context**

n/a

The issue mentions no files, tests, or entry points. First clarify the folder or tag model, channel grouping behavior, and notification rules; done should include a defined, agreed scope for organizing channels and configuring their notifications.

Written by the indexing model from the issue text.