Fix media type inference for URLs with query parameters

[fedexman]

Fix media type inference for URLs with query parameters

When using presigned URLs (eg AWS S3) with ImageUrl, AudioUrl, or VideoUrl, the media type inference fails

https://pics.s3.ap-northeast-1.amazonaws.com/test/Capture-2025-11-21-112402.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=fdafdas%2F20251121%2Fap-northeast-1%2Fs3%2Faws4_request&X-Amz-Date=20251121T023200Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Security-Token=IQoJb3JpZ2luX2VjEDoaD

to the agent we get this error,

Internal server error: Could not infer media type from image URL: 
...
Explicitly provide a `media_type` instead

the reason is that the _infer_media_type function only check the end of the url with url.endswith('.mkv') but do not parse the url.

I propose to parse the url with

from urllib.parse import urlparse
path = urlparse(self.url).path
if path.endswith('.mkv'):
            return 'video/x-matroska'