feat: implement attachement preview

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

src/services/transceive.ts

@@ -188,6 +188,25 @@ export function transceiveDownload<TRequest>(
   return { transaction: request.transaction };
 }
 
+export async function transceiveBlob<TRequest>(operation: string, data: TRequest): Promise<Blob> {
+  const request: ApiRequest<TRequest> = {
+    version: API_VERSION,
+    transaction: generateTransactionId(),
+    operation,
+    data,
+  };
+  let blob: Blob | null = null;
+  await fetchWrapper.post(API_URL, request, {
+    headers: { 'Accept': '*/*' },
+    onStream: async (response: Response) => {
+      blob = await response.blob();
+    },
+  });
+  if (blob === null) throw new Error(`[${operation}] Empty preview response`);
+  return blob;
+}
+
+
 function appendHiddenField(form: HTMLFormElement, name: string, value: string): void {
   const input = document.createElement('input');
   input.type = 'hidden';