Add server roles for Twitch Cheer/Bit Reward levels

It's nice to have a Subscriber channel on my server, which I open up to anyone who is subscribed, but I also want to let people who have cheered with bits access said channel.

And it would be a way for viewers to get perpetual access to said channel as well, which I feel is a nice thing to enable.

The roles could match the current emote levels:
* 1000
* 5000
* 10000