feat(azure): add vm_id to KVP telemetry event keys

[peytonr18]

Proposed Commit Message

feat(azure): add vm_id to KVP telemetry event keys

Add VM ID to the KVP (Key-Value Pair) event key format to improve
telemetry tracking and debugging capabilities for Azure/Hyper-V
deployments.

Additional Context

The VM ID is now queried during HyperVKvpReportingHandler initialization and appended to each event key.
Changes include:

• Query vm_id during HyperVKvpReportingHandler initialization
• Store vm_id as instance attribute with fallback to zero-guid string
• Update _event_key_format_parts() to include vm_id in key structure
• Update event key format to:
  CLOUD_INIT|<incarnation>|<event_type>|<event_name>|<uuid>|<vm_id>[|subevent_index]
• Added test_vm_id_fallback_to_zero_guid unit test to verify fallback logic.
• Production test shows vm_id in key, where vm_id is 26bd6c2f-ecc6-4b04-9f79-e500096ee45b:

CLOUD_INIT|1762458786|finish|modules-final|b8398a61-459c-4e35-95fd-c3a099396a02|26bd6c2f-ecc6-4b04-9f79-e500096ee45b{"name":"modules-final","type":"finish","ts":"2025-11-06T19:53:30.941724+00:00","result":"SUCCESS","msg":"running modules for final"}

Merge Type

• Squash merge using "Proposed Commit Message"

[KsenijaS]

can we also log the event where query for vm id was successful?

[cjp256]

was this done late to avoid circular imports?

[peytonr18]

Yeah that was exactly why - I kept getting an error message about that. Let me know if there is a better way to avoid that circular import!

[holmanb]

Generally a circular import error indicates a lack of clear hierarchy in the code. The reporting code is currently not coupled to any particular cloud, but after this change that would no longer be true.

I haven't put much thought into it, but since query_vm_id is currently not used anywhere it could just get relocated to this module.

[peytonr18]

A request was made outside of this PR to re-order uuid and vm_id to ensure RdAgent can distinguish the key, which is the reason for the change in the most recent commit.