Added getter for checking if initialization is completed

src/lib/components/base/BaseComponent.js

@@ -51,6 +51,15 @@ export class BaseComponent {
     return this.#container;
   }
 
+  /**
+   * Check if the component is initialized already. If not checked, subsequent calls to the `initialize` method will
+   * throw an error.
+   * @return {boolean}
+   */
+  get isInitialized() {
+    return this.#isInitialized;
+  }
+
   /**
    * Emit the custom event on the container element.
    * @param {keyof HTMLElementEventMap|string} event The event name.