Initial full-text search in ES|QL

[ChrisHegarty]

Meta issue listing tasks and subtasks for consideration as part of the Initial Search in ES|QL initiative.

• Basic filtering: ES|QL Search: allow WHERE with text predicates #110132
• Basic search / ranking
• Rescoring / Reranking
• Custom Scoring
• Logical / physical plan limit
• Enable multi-node
• knn basic KNN support in SEARCH for ES|QL #110054
• MATCH should use the default index analyzers
• ..

relates #109518

POCs/discovery:

• options for full text support (fuzziness, analyzers, prefix_length etc)
• RRF
• semantic text support
• feature extraction
• inference service interaction

Enhacements outside of #109518:

• support for query params to accept arrays of values (maintains readability for knn)

[elasticsearchmachine]

Pinging @elastic/es-search (Team:Search)

[ioanatia]

With #110132 merged we should have the basic filtering case covered. I think it was the only piece that was missing. Let me know if there's something else needed, but I am marking that as completed.