[DOCS] Improve serverless operation summaries

[lcawl]

Now that #2314 is fixed, we can have operation summaries that diverge from operation descriptions. This meta-issue tracks the operation summary review and edits for the serverless APIs in each of these sections:

NOTE: The readme for how to add the summary is here and the style guide is here

You can get an indication of which summaries are too long and/or contain inappropriate terms by running make lint-docs or spectral lint output/openapi/elasticsearch-serverless-openapi.json --ruleset .spectral.yaml.

Todo

• Eql
• Esql
• Graph
• Ingest
• Query rules
• Search application
• Sql
• Synonyms

In progress

• Logstash [OpenAPI] Edits Logstash pipeline APIs #3073
• Search [OpenAPI] Edit multi search and scroll API #3053, [OpenAPI] Edit search API summaries #3080, ...

Done

• Alias APIs Update summaries for several endpoints #2718
• Analyze [OpenAPI] Improve analyze and async search summaries #2924
• Application [OpenAPI] Edit search application summaries #2926
• Async search [OpenAPI] Improve analyze and async search summaries #2924
• Bulk Add more summaries #2719
• Cat Add further summaries #2734
• Component template Add more summaries #2719
• Connector [OpenAPI] Edits connector API summaries #3051
• Data stream [DOCS] Add operation summaries for data stream APIs #2711
• Delete by query Add further summaries #2734
• Doc Add further summaries #2734
• Document [OpenAPI] Edit mget, multi term vectors, and terms enum APIs #3052
• Enrich Add further summaries #2734
• Index template Add operation summaries for index template APIs #2634
• Inference
• Info Add further summaries #2734
• License Update summaries for several endpoints #2718
• Lifecycle Update summaries for several endpoints #2718
• ML: Add summaries for machine learning APIs #2453, ...
• Mapping Add further summaries #2734
• Refresh Update summaries for several endpoints #2718
• Reindex Update summaries for several endpoints #2718
• Rollover Update summaries for several endpoints #2718
• Root Add summaries for root operations #2732
• Scripts Add more summaries #2719, [OpenAPI] Edit script language and context APIs #3054
• Security Add more summaries #2719, [OpenAPI] Edit summaries for security APIs #3035, [OpenAPI] Edit more security API summaries #3036
• Settings Update summaries for several endpoints #2718
• Tasks Add more summaries #2719
• Template Add operation summaries for index template APIs #2634
• Transform Add further summaries #2734
• Update by query Add further summaries #2734
• Validate Add further summaries #2734