metrics: support go-memstats-inuse and estimate-inuse (#43151) (#46117)

close #46120

Author: ti-chi-bot

metrics/grafana/tidb_runtime.json

@@ -142,11 +142,19 @@
               "refId": "A"
             },
             {
-              "expr": "go_memstats_alloc_bytes{k8s_cluster=\"$k8s_cluster\",tidb_cluster=\"$tidb_cluster\", instance=~\"$instance\"}",
+              "expr": "go_memstats_next_gc_bytes{k8s_cluster=\"$k8s_cluster\",tidb_cluster=\"$tidb_cluster\", instance=~\"$instance\"} / (1 + tidb_server_gogc{k8s_cluster=\"$k8s_cluster\",tidb_cluster=\"$tidb_cluster\", instance=~\"$instance\"} / 100)",
               "format": "time_series",
               "hide": false,
               "intervalFactor": 1,
               "legendFormat": "estimate-inuse",
+              "refId": "I"
+            },
+            {
+              "expr": "go_memstats_alloc_bytes{k8s_cluster=\"$k8s_cluster\",tidb_cluster=\"$tidb_cluster\", instance=~\"$instance\"}",
+              "format": "time_series",
+              "hide": false,
+              "intervalFactor": 1,
+              "legendFormat": "go-memstats-inuse",
               "refId": "H"
             },
             {