chore: add tx metrics and logs for serialization errors (#15215)

Before db_metrics were all or nothing. Now `InTx` metrics are always recorded, and query metrics are opt in.


Adds instrumentation & logging around serialization failures in the database.

enterprise/coderd/workspacequota.go

@@ -104,8 +104,9 @@ func (c *committer) CommitQuota(
 		permit = true
 		consumed = newConsumed
 		return nil
-	}, &sql.TxOptions{
-		Isolation: sql.LevelSerializable,
+	}, &database.TxOptions{
+		Isolation:    sql.LevelSerializable,
+		TxIdentifier: "commit_quota",
 	})
 	if err != nil {
 		return nil, err