async media: add ability to upload media asynchronously

Co-authored-by: Tulir Asokan <tulir@maunium.net>

mautrix_telegram/util/parallel_file_transfer.py

@@ -317,6 +317,7 @@ async def parallel_transfer_to_matrix(
     filename: str,
     encrypt: bool,
     parallel_id: int,
+    async_upload: bool = False,
 ) -> DBTelegramFile:
     size = location.size
     mime_type = location.mime_type
@@ -340,7 +341,11 @@ async def parallel_transfer_to_matrix(
             data = encrypted(data)
             up_mime_type = "application/octet-stream"
         content_uri = await intent.upload_media(
-            data, mime_type=up_mime_type, filename=filename, size=size if not encrypt else None
+            data,
+            mime_type=up_mime_type,
+            filename=filename,
+            size=size if not encrypt else None,
+            async_upload=async_upload and not encrypt,
         )
         if decryption_info:
             decryption_info.url = content_uri