Sandbox: Make `window.monaco` and `window.Prism` available for plugins inside the sandbox (#74977)

* Sandbox: Make `window.monaco` available for plugins inside the sandbox

* Add Prism as an endowment

* Fix typo

public/app/features/plugins/sandbox/sandbox_plugin_loader.ts

@@ -80,6 +80,15 @@ async function doImportPluginModuleInSandbox(meta: PluginMeta): Promise<System.M
         // window.locationSandbox. In the future `window.location` could be a proxy if we
         // want to intercept calls to it.
         locationSandbox: window.location,
+        get monaco() {
+          // `window.monaco` may be undefined when invoked. However, plugins have long
+          // accessed it directly, aware of this possibility.
+          return Reflect.get(window, 'monaco');
+        },
+        get Prism() {
+          // Similar to `window.monaco`, `window.Prism` may be undefined when invoked.
+          return Reflect.get(window, 'Prism');
+        },
         // Plugins builds use the AMD module system. Their code consists
         // of a single function call to `define()` that internally contains all the plugin code.
         // This is that `define` function the plugin will call.