Add Twitch IRC Support

[nyancrimew]

requirements appear to be setting the password and getting capabilities, twitch irc is documented quite well in their docs at https://dev.twitch.tv/docs/irc/authenticate-bot/

[Dpeta]

holy glubbing bingle,,

Twitch support would definitely be possible & silly, I've actually played around with it a bit before

[Dpeta]

Added a PASS field & twitch.tv/membership cap req with https://github.com/Dpeta/pesterchum-alt-servers/commit/14935a23ce9bc5de17e36677cbe248461d7fa8b1 & https://github.com/Dpeta/pesterchum-alt-servers/commit/da8e6ddbf7af0ee3cc4222875ebfa67a79c61dca, not actual proper support but seems to work given that:

• oauth pass scope has chat:edit+chat:read+whispers:read+whispers:edit
• nick/handle is identical to twitch name
• any channels joined are lowercase

[Dpeta]

Added an IRC compatibility option to stop Pesterchum from sending it's silly syntax & an option to force messages to have initials, so twitch!pchum/irc!pchum ought to be more usable now :3 (https://github.com/Dpeta/pesterchum-alt-servers/pull/120 + https://github.com/Dpeta/pesterchum-alt-servers/commit/a7f266c3822413a696f005136f3adb7e2966063a)