Deprecated: Please refer to the new method.
Download a MX Map's image. Check the Content-Header's content-type
for the image file type. Will return empty result if no image is available (...under the specified position).
https://tm.mania.exchange/maps/{id}/image/{pos} // TM2.MX
https://trackmania.exchange/maps/{id}/image/{pos} // TMX
https://sm.mania.exchange/maps/{id}/image/{pos} // SMX