Prioritize joining channels that are currently visible to the user.

[mastondzn]

When you have bad internet and a good amount of tabs it becomes kind of annoying that you have to wait a bit for c2 to actually join the channels that you see, and that happens on each reconnect.

[pajlada]

I am hesitant about adding too much complexity for this given the EventSub chat implementation won't have this issue, however I would be open to a PR for this if it's simple enough (e.g. just a sort in a list)