workload: add querylog workload generator

Adds a querylog workload generator that generates and executes the
queries based on the provided query log (according to the frequency
of the queries found in the log). It assumes that the corresponding
data has already been loaded and attempts to simulate the workload
that was captured by the log.

Release note: None

pkg/ccl/workloadccl/allccl/all.go

@@ -23,6 +23,7 @@ import (
 	_ "github.com/cockroachdb/cockroach/pkg/workload/kv"
 	_ "github.com/cockroachdb/cockroach/pkg/workload/ledger"
 	_ "github.com/cockroachdb/cockroach/pkg/workload/querybench"
+	_ "github.com/cockroachdb/cockroach/pkg/workload/querylog"
 	_ "github.com/cockroachdb/cockroach/pkg/workload/queue"
 	_ "github.com/cockroachdb/cockroach/pkg/workload/rand"
 	_ "github.com/cockroachdb/cockroach/pkg/workload/sqlsmith"