encode content before counting

[pvgenuchten]

Overview

python counts string length differently when having special characters, therefore an incorrect content length is sent, and the request is truncated, count is correct if it is first encoded

Related Issue / Discussion

fixes #1091

Additional Information

to be discussed if it makes sense to return also the content itself encoded

Contributions and Licensing

(as per https://github.com/geopython/pycsw/blob/master/CONTRIBUTING.rst#contributions-and-licensing)

• I'd like to contribute [feature X|bugfix Y|docs|something else] to pycsw. I confirm that my contributions to pycsw will be compatible with the pycsw license guidelines at the time of contribution.
• I have already previously agreed to the pycsw Contributions and Licensing Guidelines