dbconsole: add elastic io token exhausted duration to overload page

This patch adds the metric `elastic_io_tokens_exhausted_duration.kv`
introduced in cockroachdb#124078.

Informs cockroachdb#121572.

Release note (ui change): The `Admission IO Tokens Exhausted` chart now
separates elastic and regular io work.

pkg/ui/workspaces/db-console/src/views/cluster/containers/nodeGraphs/dashboards/overload.tsx

@@ -73,21 +73,30 @@ export default function (props: GraphDashboardProps) {
     </LineGraph>,
 
     <LineGraph
-      title="KV Admission IO Tokens Exhausted Duration Per Second"
+      title="Admission IO Tokens Exhausted Duration Per Second"
       sources={nodeSources}
       tenantSource={tenantSource}
       showMetricsInTooltip={true}
       tooltip={`Relative time the node had exhausted IO tokens for all IO-bound work per second of wall time, measured in microseconds/second. Increased IO token exhausted duration indicates IO resource exhaustion.`}
     >
       <Axis label="Duration (micros/sec)">
         {nodeIDs.map(nid => (
-          <Metric
+          <>
+            <Metric
+              key={nid}
+              name="cr.node.admission.granter.io_tokens_exhausted_duration.kv"
+              title={"Regular (Foreground) IO Exhausted " + nodeDisplayName(nodeDisplayNameByID, nid)}
+              sources={[nid]}
+              nonNegativeRate
+            />
+            <Metric
             key={nid}
-            name="cr.node.admission.granter.io_tokens_exhausted_duration.kv"
-            title={"IO Exhausted " + nodeDisplayName(nodeDisplayNameByID, nid)}
+            name="cr.node.admission.granter.elastic_io_tokens_exhausted_duration.kv"
+            title={"Elastic (Background) IO Exhausted " + nodeDisplayName(nodeDisplayNameByID, nid)}
             sources={[nid]}
             nonNegativeRate
-          />
+            />
+          </>
         ))}
       </Axis>
     </LineGraph>,