feat: implement attachement preview

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

src/services/entityService.ts

@@ -2,7 +2,7 @@
  * Entity management service
  */
 
-import { transceivePost, transceiveStream, transceiveDownload } from './transceive';
+import { transceivePost, transceiveStream, transceiveDownload, transceiveBlob } from './transceive';
 import type {
   EntityFetchRequest,
   EntityFetchResponse,
@@ -28,6 +28,7 @@ import type {
   EntityPatchResponse,
   EntityPatchRequest,
   EntityDownloadRequest,
+  EntityPreviewRequest,
   EntityBlobsRequest,
   EntityBlobsResponse,
   EntityBlobsWireResponse,
@@ -231,6 +232,10 @@ export const entityService = {
     return transceiveDownload<EntityDownloadRequest>('entity.download', request);
   },
 
+  async preview(request: EntityPreviewRequest): Promise<Blob> {
+    return await transceiveBlob<EntityPreviewRequest>('entity.preview', request);
+  },
+
   /**
    * Fetch one or more message parts (attachments) inline for rendering.
    *