Chat pipeline: redirect messages to other channels

With the existing log/ChatProcessor, allow a limited subset of in-AP-client messages to trigger sending a message to a different output channel - e.g., send an in-game hint to the hint channel instead the general chat.

Use a simplified syntax:

• chat message begins with #hint
• optional from:"world" that the Overseer can use to look up the source world
• w/ #70 (closed), consider adding a "verbatim" hint type to track and display