stacked on v2-updreqresp: Process update, Send+Ack result

[jw-msft]

Note: this is a stacked PR atop user/jw-msft/v2-updreqresp branch

• Pick work off of work queue when in Processing Update state and invoke adu_processupdate on it
• Add adu_integration that copies the bare essential necessary functions from adu_interface and agent workflow with some modifications
• Condense all main update orchestration flow into single function in new adu_processupdate.cpp
• Generate report JSON for success and failures and publish it with updrslt_req message and transition to REPORT_RESULTS state
• Wait for and verify PUBACK from the broker for the subscribe and transition to REPORT_RESULTS_ACK state
• Wait for and verify ACK msg published by ADU service on the subscribe response topic and transition to IDLEWAIT