Add statement-level statistics to the query plan cache (or elsewhere)

The current timeseries implementation allows us to infer how often WT I/O requests result in a WT cache hit vs not.

I define a logical I/O as a single request for a block or page (whatever our most granular request is) whether from cache or disk.

Is there explicit tooling that would let us

• aggregate the actual number of logical I/Os for a given query shape
• aggregate the actual number of logical I/Os for all query shapes

and then for the above

• aggregate the number of times the logical I/O was serviced by a WT cache hit
• aggregate the number of times the logical I/O was serviced by a filesystem cache hit
• aggregate the number of times the logical I/O resulted in a physical I/O request