[Feature] Add NestedField Visit Method

[luyuncheng]

i use neural query in OpenSearch with nested field https://opensearch.org/docs/latest/search-plugins/semantic-search/#setting-a-default-model-on-an-index-or-field, but it can not calling model in search pipeline with neural_query_enricher processor like the doc shows.

i think it is because NestedQueryBuilder do not support visit method like boolean query

OpenSearch/server/src/main/java/org/opensearch/index/query/BoolQueryBuilder.java

Lines 432 to 439 in 581fcd2

	public void visit(QueryBuilderVisitor visitor) {
	visitor.accept(this);
	if (mustClauses.isEmpty() == false) {
	QueryBuilderVisitor subVisitor = visitor.getChildVisitor(Occur.MUST);
	for (QueryBuilder mustClause : mustClauses) {
	mustClause.visit(subVisitor);
	}
	}

it can not visit from processRequest like the following code do:
https://github.com/opensearch-project/neural-search/blob/2b21110be2d343e83f539e75104a8928522bf720/src/main/java/org/opensearch/neuralsearch/processor/NeuralQueryEnricherProcessor.java#L68-L75

BTW in #13837 i see it fixed many scenarios queries, but we still need NestedQueryBuilder to visit query builder.

so this pr i added a visit method.

[github-actions]

❌ Gradle check result for e72e9b3: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[IanMenendez]

Having this same problem. NeuralQueryEnricher search processor does not support Nested Fields

[opensearch-trigger-bot]

This PR is stalled because it has been open for 30 days with no activity.

[zhichao-aws]

Hi @luyuncheng, I created a PR to fix the same issue and found there is duplicate PR. Are you still working at this PR?

[luyuncheng]

Hi @luyuncheng, I created a PR to fix the same issue and found there is duplicate PR. Are you still working at this PR?

@zhichao-aws
#14739 Looks like the same solution, but my pr waiting for a month, nobody triggered. if you merged, we can close this.

[opensearch-trigger-bot]

This PR is stalled because it has been open for 30 days with no activity.