Add async_iterable_to_stream utility to avoid aiohttp compatibility issues

Create async_iterable_to_stream() in gns3server.utils.asyncio that
converts an async iterable to an aiohttp StreamReader via a background
feeder task. This bypasses aiohttp's AsyncIterablePayload which can
cause 'Connection reset by peer' with certain HTTP servers.

Use it in _run_http_query for the __aiter__ data path.

gns3server/controller/compute.py

@@ -32,7 +32,7 @@ else:
     from async_timeout import timeout as asynctimeout
 
 from ..utils import parse_version
-from ..utils.asyncio import locking
+from ..utils.asyncio import locking, async_iterable_to_stream
 from ..controller.controller_error import (
     ControllerError,
     ControllerBadRequestError,
@@ -537,6 +537,7 @@ class Compute:
                 elif hasattr(data, "__aiter__"):
                     chunked = True
                     headers["content-type"] = "application/octet-stream"
+                    data = await async_iterable_to_stream(data)
                 # If the data is an open file we will iterate on it
                 elif isinstance(data, io.BufferedIOBase):
                     chunked = True