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

package.json

@@ -18,8 +18,7 @@
     "e2e:enterprise:dev": "./e2e/start-and-run-suite enterprise dev",
     "e2e:enterprise:debug": "./e2e/start-and-run-suite enterprise debug",
     "e2e:playwright": "yarn playwright test",
-    "e2e:playwright:ui": "yarn playwright test --ui",
-    "e2e:playwright:report": "yarn playwright show-report",
+    "e2e:playwright:server": "./e2e/plugin-e2e/start-and-run-suite",
     "test": "jest --notify --watch",
     "test:coverage": "jest --coverage",
     "test:coverage:changes": "jest --coverage --changedSince=origin/main",