Batch checking live status for all channels after startup.

[xel86]

Pull request checklist:

• CHANGELOG.md was updated, if applicable

Description

On startup, each channel currently individually make an api call to update its own live status on roomId change, this behavior will be unchanged.

Instead of having a timer for each individual channel to call to refresh its own live status, we will have a single timer in TwitchIrcServer that will update the live status of every channel at once in a single api call. Currently I have this set on a 30 second interval. This will be updated faster than the current 60 second interval, but since we are only making a single api call it will still result in an overall performance gain.

Similar logic for NotificationController::fetchFakeChannels() mentioned in the connected issue was already done in PR #3442

Closes #3009

[zneix]

I'll comment more things later because someone had to, as always, make my changes before me.

[zneix]

As discussed in chat, I'm happy with duplicating logic from TwitchAccount.cpp/NotificationController.cpp here. I will try to make a util wrapping all of these, but that's something for another PR though.

Gonna test this locally first.

[zneix]

While we still make a burst of requests upon starting up the application, this is already a very good improvement 👍

[Mm2PL]

one little typo and merging :)