Currently the only user-available means to get ahold of the query shape hash for a given query, one can either:

• Wait & spot the query shape hash in the slow query log.
• Invoke setQuerySettings on the given query, and later query via the $querySettings aggregation stage to see the query shape hash.

To improve user experience, we should make that the query shape hash is readily available in the explain output via a new queryShapeHash, if present.

The new field queryShapeHash should be available on top-level explain output (i.e. accessible via explain.queryShapeHash), and would ideally be positioned under explain.command.

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To minimise confusion going forward, We need to make sure to rename every occurrence of the plan-cache specific shape hash:

• from: "queryHash"
• to: "planCacheShapeHash"

This change should be done for both code naming conventions, and especially for field names in user-facing output such as: explain, plan cache stats, currop.

Note: This change will require downstream attention.