Plugin extensions: Add e2e tests (#89048)

* add custom plugins

* update bundles

* provision app plugins and their dashboards

* add one more script that run e2e tests using e2e test server

* add e2e tests

* regenerate jsonnet dashboards

* ignore custom plugins and playwright report

* use minified

* cleanup tests

* update codeowners

* add leading slash

* document new script

* document custom-plugins

* cleanup

* twist modules

* add readme

e2e/custom-plugins/app-with-extensions/plugin.json

@@ -0,0 +1,49 @@
+{
+  "$schema": "https://raw.githubusercontent.com/grafana/grafana/main/docs/sources/developers/plugins/plugin.schema.json",
+  "type": "app",
+  "name": "Extensions App",
+  "id": "myorg-extensions-app",
+  "preload": true,
+  "info": {
+    "keywords": ["app"],
+    "description": "Example on how to extend grafana ui from a plugin",
+    "author": {
+      "name": "Myorg"
+    },
+    "logos": {
+      "small": "img/logo.svg",
+      "large": "img/logo.svg"
+    },
+    "screenshots": [],
+    "version": "1.0.0",
+    "updated": "2024-06-11"
+  },
+  "includes": [
+    {
+      "type": "page",
+      "name": "Default",
+      "path": "/a/myorg-extensions-app",
+      "role": "Admin",
+      "addToNav": true,
+      "defaultNav": true
+    }
+  ],
+  "dependencies": {
+    "grafanaDependency": ">=10.3.3",
+    "plugins": []
+  },
+  "extensions": [
+    {
+      "extensionPointId": "grafana/dashboard/panel/menu",
+      "type": "link",
+      "title": "Open from time series or pie charts (path)",
+      "description": "This link will only be visible on time series and pie charts"
+    },
+    {
+      "extensionPointId": "grafana/dashboard/panel/menu",
+      "type": "link",
+      "title": "Open from time series or pie charts (onClick)",
+      "description": "This link will only be visible on time series and pie charts"
+    }
+  ]
+}