Do not log server response based on content length but content type

We are currently logging the server's response based on the content length. This is problematic as we can see in the attached log of SUPNXP-26503 where PNG and PDF files are printed in logs. This has another performance penality because, as seen in NXPY-100, calling resp.text will trigger chardet and the whole encoding detection mecanism.

So we can do clever by logging based on the content type.