Update query syntax to support structured metadata search

[jordanpadams]

Are you sure this is not a new requirement or bug?

Yes

Task Type

Sub-task

💡 Description

Update Registry API query syntax to fully support structured metadata search. This includes:

• Enabling queries against nested/structured PDS4 XML attributes in OpenSearch
• Updating query parsing to route requests to structured metadata fields
• Ensuring backward compatibility with existing flat metadata queries during transition

Related:

• Complete Transition to Full Structured XML Metadata in Registry #768 (B18 structured XML theme)
• Add Initial Support for Searching Full PDS4 Structured Metadata #632 (initial structured metadata support)