https://issues.apache.org/jira/browse/SOLR-17813

Description

Apache Lucene implemented a version of knn vector query called SeededKnnVectorQuery that provides a query seed to initiate the vector search (entry points in the HNSW graph exploration) based on Lexically-Accelerated Dense Retrieval

Solution

This PR introduces a new optional parameter for the current KNN query parser: seedQuery.
The seed parameter can be any valid Solr query, allowing traditional query logic to guide the vector search in a hybrid-like way.

Added a new method getSeedQuery() that parses the seed parameter and returns the corresponding Lucene Query.

When a seed query is present, the KNN vector query is wrapped with SeededKnnVectorQuery:

• SeededKnnVectorQuery.fromFloatQuery(...) for FLOAT32 vectors.

• SeededKnnVectorQuery.fromByteQuery(...) for BYTE vectors.

If no seedQuery is provided, the parser behaves as before and executes a "standard" KNN query.

Tests

• Test to verify that when the seedQuery parameter is provided, the SeededKnnVectorQuery is executed (both float and byte).
• Test to verify that when the seedQuery parameter is provided but blank, Solr throws a BAD_REQUEST exception.
• Test to verify that when the seedQuery parameter is provided with an invalid value, Solr throws a BAD_REQUEST exception.
• Test to verify that when the seedQuery parameter itself is a knn query, it is correctly parsed and applied as the seed for the main knn query.
• Test to verify that when both seedQuery and early termination parameters are provided, the PatienceKnnVectorQuery is executed using the SeededKnnVectorQuery.

Checklist

Please review the following and check all that apply:

• I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
• I have given Solr maintainers access to contribute to my PR branch. (optional but recommended, not available for branches on forks living under an organisation)
• I have developed this patch against the main branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• I have added documentation for the Reference Guide