[asset manager] Research usage of ES|QL to power API endpoints

[miltonhultgren]

With the release of ES|QL, it would be interesting to investigate if/how it may help solve some of the problems the API tries to solve today:

• Can it make the signal backed grouping faster
• Can it sort the grouped assets
• Can it connect the assets to their metrics
• Can it walk the graph in steps

[elasticmachine]

Pinging @elastic/observability-asset-management (Team:Observed Asset Management)

[elasticmachine]

Pinging @elastic/obs-knowledge-team (Team:obs-knowledge)