Add support for projection on unmapped fields with Elasticsearch

Description

Currently, we throw a SearchException for projections on fields that are not mapped to an entity (HSEARCH400019), whereas Lucene accepts that.

Since there already is an implementation of projection extraction without metadata (which is about to be removed, see HSEARCH-2470), we might as well reuse that implementation for unknown fields. It may be what was originally intended.

Environment

None

Assignee

Yoann Rodière

Reporter

Yoann Rodière

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Priority

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