Fixes include:
1) users can now opt out of being mkov'd, instead their messages
will be ascii blocked out.
2) highlights are avoided, by learning names from the main tvl
channel and adding a dot after the first char, for example:
> 21:31:35 <•eta-eb> m.ulti: bas1l we quickly connect controller is mostly agreed
3) highlight avoidance is now stored in redis, to avoid restarts
from destroying the map and causing a bunch of highlights
upon restart
Change-Id: I1055992aab3a06aa1f4ba937fc3ef45f2f78cedc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2054
Tested-by: BuildkiteCI
Reviewed-by: cynthia <cynthia@tvl.fyi>
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: ben <tvl@benjojo.co.uk>
