Switch ClemBot.Bot messenger to a guild queue based approach

[Jay-Madden]

This is to prevent api overloads when a singular guild gets a large burst of events which has begun to happen more frequently and leads to connection exhaustion. The implementation of this will be somewhat complex and a primary goal should be easy visibility into the current state of the queues. as well as a push based approach to dispatching instead of a polling based.

Points of discussion:
Should this be per guild queue or per guild per event queue

Notes:

There should be a method exposed to bypass the queue and instantly invoke an event. this is needed for message events to so that invoking a command does not wait on background events to finish processing

[Jay-Madden]

Closed in #609