* server: log request/response sizes for event triggers
event triggers (and scheduled triggers) now have request/response size
in their logs.
* add changelog entry
This also seems to squash a stubborn space leak we see with
subscriptions (linking to canonical #3388 for reference).
This may also fix some of the "Unexpected exception" websockets
exceptions we are now surfacing (see e.g. #4344)
Also: dev.sh: fix hpc reporting
Initial work on this done by Vamshi.
