Avoid exhaustive score mode in QueryPhaseCollector

[reugn]

Addresses the two TODOs in QueryPhaseCollector.scoreMode:

• when the top docs and the aggs collector only disagree on whether they need scores, the score mode is now TOP_DOCS_WITH_SCORES instead of COMPLETE. Aggs do report these score modes, see CompositeAggregator and GlobalOrdCardinalityAggregator.
• with min_score, TOP_DOCS now becomes TOP_DOCS_WITH_SCORES and TOP_DOCS_WITH_SCORES is left alone, instead of both becoming COMPLETE.

In both cases we get the scores we need without asking for exhaustive collection. The rest of the behaviour is unchanged: COMPLETE_NO_SCORES with min_score still becomes COMPLETE, skipping is still up to the collectors, and setMinCompetitiveScore is still ignored when aggs are collected.

Adds two tests that run real searches with real collectors, one per case.

Closes #97271

[elasticsearchmachine]

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

[elasticsearchmachine]

Hi @reugn, I've created a changelog YAML for you.

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ℹ️ Important: Docs version tagging

👋 Thanks for updating the docs! Just a friendly reminder that our docs are now cumulative. This means all 9.x versions are documented on the same page and published off of the main branch, instead of creating separate pages for each minor version.

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