Issue: ENG-5149.
Protocol diagram: notion doc.
- We want to send request to Tunnelbroker to send message to device.
- We add clientMessageID because Tunnelbroker has to know which message to confirm later.
- Using clientMessageID - not simple messageID because Tunnelbroker will assign another ID based od timestamp (messages needs to be sorted).
- Adding this ID will also fix problem when two separate Tunnelbroker instances will get message for the same recipient in exactly the same time.
Depends on D9461