Plugins: Introduce new Flame graph panel (#56376)

* Flamegraph

* Updated flame graph width/height values

* Fix top table rendering issue

* Add feature toggle for flamegraph in explore

* Update tests

* Hide flamegraph from dash panel viz list if feature toggle not enabled

* Show table if no flameGraphFrames

* Add flame graph to testdata ds

* Minor improvement

pkg/tests/api/plugins/data/expectedListResp.json

@@ -427,6 +427,42 @@
     "signatureType": "",
     "signatureOrg": ""
   },
+  {
+    "name": "Flame Graph",
+    "type": "panel",
+    "id": "flamegraph",
+    "enabled": true,
+    "pinned": false,
+    "info": {
+      "author": {
+        "name": "Grafana Labs",
+        "url": "https://grafana.com"
+      },
+      "description": "",
+      "links": null,
+      "logos": {
+        "small": "public/img/icn-panel.svg",
+        "large": "public/img/icn-panel.svg"
+      },
+      "build": {},
+      "screenshots": null,
+      "version": "",
+      "updated": ""
+    },
+    "dependencies": {
+      "grafanaDependency": "",
+      "grafanaVersion": "*",
+      "plugins": []
+    },
+    "latestVersion": "",
+    "hasUpdate": false,
+    "defaultNavUrl": "/plugins/flamegraph/",
+    "category": "",
+    "state": "beta",
+    "signature": "internal",
+    "signatureType": "",
+    "signatureOrg": ""
+  },
   {
     "name": "Gauge",
     "type": "panel",
@@ -1702,4 +1738,4 @@
     "signatureType": "",
     "signatureOrg": ""
   }
-]
+]