To help reduce the volume of logs during the happy path of flow registration, there will only be one log message reported when a flow is completed.
There are additional fields added to all flow log messages:
1. `src`: local address
2. `dst`: origin address
3. `durationMS`: capturing the total duration of the flow in milliseconds
Additional logs were added to capture when a flow was migrated or when cloudflared sent off a registration response retry.
Closes TUN-8701
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