Add verified fake coverage for advanced Model Target workflows

[adamtheturtle]

Follow-up to #3191.

The current verified fake happy-path coverage exercises standard Model Target dataset create/status/delete, while advanced datasets have usage-level mock coverage. Add verified fake tests against real Vuforia for advanced dataset create/status/download/delete, then adjust the mock if the real advanced workflow differs from the current implementation.

Acceptance criteria:

• Verified fake tests cover advanced dataset creation, status polling, download, and deletion across real and mock backends.
• The mock matches any observed advanced-specific response differences.
• The tests are assigned to a CI pattern and pass with the generated Model Target credentials.