Remove obselete correlation_id handling from code

[keithralphs]

Before tracing was added to the codebase, Callum had implemented a manually managed correlation_id which is passed round on the internal event system. This is no longer required as the trace_id from the Open Telemetry tracing implementation provides this identifier. The manual correlationId should therefore be removed from the code ensuring that, where necessary, propagation of the Trace context ensures that the record of the chain of events is maintained. The likely area for this is the propagation of event from the server to CLI via the message bus where the context should be transmitted via the stmp headers as is already implmentaed for Bluesky documents. The apporpiate functions from the observability-uttils library can be used for this purpose.