feat(data): add method that checks if data item has been saved

src/app/modules/data/data.provider.ts

@@ -147,4 +147,13 @@ export class DataProvider {
   async search(query: SCSearchQuery): Promise<SCSearchResponse> {
     return (await this.client.search(query));
   }
+
+  /**
+   * Provides information if something with an UID is saved as a data item
+   *
+   * @param uid Unique identifier of the saved data item
+   */
+  async isSaved(uid: string): Promise<boolean> {
+    return this.storageProvider.has(this.getDataKey(uid));
+  }
 }