[PROPOSAL] Block hybrid query in case there are no search pipeline

What/Why

What are you proposing?

New validation that should detect if hybrid query is executed without any search pipeline attached, meaning there are none of the inlined, request param or index default pipeline that system can resolve for a search request.

What users have asked for this feature?

Currently if there are no resolvable search pipeline then hybrid query will silently accepts it and return results in internal format that are not relevant to user query results.

What problems are you trying to solve?

Incorrect results that may be misleading, introduce fail fast behavior so incorrect search configuration can be fixed faster.

What is the developer experience going to be?

Same/no change in API

Are there any breaking changes to the API

System may start returning error instead of incorrect result

Why should it be built? Any reason not to?

Pipeline configuration is manual and error prone process, by design hybrid query needs both components - query and pipeline, but they are not directly connected and misconfiguration is possible

What will it take to execute?

We should be able to resolve pipelines at coordinator level inside hybrid query builder