[3.x] Check status code when downloading file (#1079)

* Check status code when downloading file and raise an error if someting bad happends

* Style fixes

* Add doc

* Use "towncrier create <issue>.<type>" for creating file

tests/mocked_bot.py

@@ -37,7 +37,11 @@ class MockedSession(BaseSession):
         return response.result  # type: ignore
 
     async def stream_content(
-        self, url: str, timeout: int, chunk_size: int
+        self,
+        url: str,
+        timeout: int,
+        chunk_size: int,
+        raise_for_status: bool,
     ) -> AsyncGenerator[bytes, None]:  # pragma: no cover
         yield b""