fix: Handle errors from event stream callbacks

[tpoliaw]

If a callback raises an exception, it shouldn't prevent other callbacks
receiving the same event. It should also not raise the exception at the
call site that published the event.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.75%. Comparing base (18489bd) to head (73206be).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1302   +/-   ##
=======================================
  Coverage   94.74%   94.75%           
=======================================
  Files          42       42           
  Lines        2741     2746    +5     
=======================================
+ Hits         2597     2602    +5     
  Misses        144      144           

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[tpoliaw]

The main symptom of this was that if a scan failed due to eg a stomp connection error, even if it reconnected, any subsequent scans would fail as the unsubscribe the tiled writer callback would never be called and tiled would return 409 conflict errors when two tiled writers tried to write the same events.