Fix clean-up script

[ydaponte]

US: As a Data Engineer I want to be able to use the clean-up script from the E2E Databricks+ADF sample so I can delete all resources automatically without the need to manual work.

DoD

• clean-up script handles key-vault hard delete
• clean-up script uses deployment_id variable to target the exact deployment
• clean-up script properly deletes the SPs that were created for that deployment
• clean-up script properly deletes the devops pipelines and service connections
• the deployment script can verify upfront if the key-vault was soft-deleted before re-deploying the solution

Ensure you've read the Contributing Guide (Microsoft Internal only.)

• [ ] Fix hard key-vault delete: #596
• [ ] Use deployment_id in clean-up script: #821