Some errors aren't useful for debugging

[KTAtkinson]

Some errors being sent to Sentry aren't useful from a debugging perspective. These errors should be filtered out. The errors in question include:

ConnectionError / ConnectionRefusedError / ConnectionResetError (if these have a nice hierarchy of exceptions and sentry's smart enough, maybe just ConnectionError would be sufficient)
HTTPError / HTTPRequestTimeout / HTTPServiceUnavailable (same)
OperationalError
TTransportException / TApplicationException / TProtocolException
MemcachedServerError