Improved performance and reliability of message queues

Improved message queue performance and reliability. Added caching mechanism for dynamic queue service call responses, which now uses a thread lock to ensure that only one get_next_packet_data request is processed at a time. Cleaned up and improved logging. Added exception handling at multiple levels in get_next_packet_data.

This fixes issues we've seen where packets can fill up with multiple messages from a static queue, even if the queue length is 1, because the dynamic queue service calls were slow enough that more messages arrived in the queue while processing a single packet.