Added initial implementation of mocks for chrome StorageArea, adding first tests for storage helper

tests/mocks/ChromeEvent.ts

@@ -0,0 +1,9 @@
+export default class ChromeEvent<T extends Function> implements chrome.events.Event<T> {
+    addListener = vi.fn();
+    getRules = vi.fn();
+    hasListener = vi.fn();
+    removeRules = vi.fn();
+    addRules = vi.fn();
+    removeListener = vi.fn();
+    hasListeners = vi.fn();
+}