Add support for chat connectors as separate microservices

[boring-nick]

It would be very useful for certain scenarios to implement chat connectors as separate services, rather than being part of supibot. For example, supibot could be restarted without connecting all of the channels.

It could also potentially simplify the inevitable forced migration to eventsub for twitch chat connections.

Current infrastructure choice is to use Redis streams. More information about planned connector design here: https://github.com/Supinic/supibot/tree/platform-connectors-manifest/connector-docs

Example connector for IRC: https://github.com/boring-nick/supibot-connector-poc