So far the SDK provided a messaging API that was not thread-safe (i.e. goroutine-safe). Additionally the SDK provided a MutexAPI which made it thread-safe at the cost of removed concurrency possibilities. The changes implemented in this commit replace both implementations with a thread-safe connection pool based solution.
The api gateway is a SDK user that requires reliable high performance send capabilities with a limit amount of amqp connections. These changes in the PR try address their requirements by moving the responsibility of connection management into the SDK. From this change other SDK users will benefit as well.
Security-concept-update-needed: false.
JIRA Work Item: STACKITALO-62
