Add a Module API for accessing storage helper functions. (#34284)

* Add a Module API for accessing the Platform.

* Drop overkill module test

* drop unused sample file

* fix import

* Update module API

* fix typo

* fix typo again

* and again

* update api

packages/module-api/element-web-module-api.api.md

@@ -63,6 +63,8 @@ export interface Api extends LegacyModuleApiExtension, LegacyCustomisationsApiEx
     readonly rootNode: HTMLElement;
     // @alpha
     readonly settings: SettingsApi;
+    // @alpha
+    readonly storageHelper: StorageHelperApi;
     readonly stores: StoresApi;
     // @alpha
     readonly widget: WidgetApi;
@@ -495,6 +497,11 @@ export interface SpacePanelItemProps {
     tooltip?: string;
 }
 
+// @alpha
+export interface StorageHelperApi {
+    getPickleKey(userId: string, deviceId: string): Promise<string | null>;
+}
+
 // @public
 export interface StoresApi {
     roomListStore: RoomListStoreApi;