[FEATURE] `ValidationResultOperation` for UC storage credential validation should include `PATH_EXISTS` and `HIERARCHICAL_NAMESPACE_ENABLED`

[qziyuan]

Problem Statement When validate UC storage credential using SDK, the returned response will contain two None operations. It's because PATH_EXISTS and HIERARCHICAL_NAMESPACE_ENABLED are missing in ValidationResultOperation

Proposed Solution Support those two missing validate operations.

Additional Context Add any other context, references or screenshots about the feature request here.

[mgyucht]

Thank you for reporting this. I've created a ticket for the Unity Catalog team to update their API definition.