Enhance the debugging output inside of __plenty_api_request

[initBasti]

We could print out the full endpoint, which was used for a request with print(raw_response.request.url). I found this to be more useful, as it shows potential problems more directly. The question is: "are the other prints for the endpoint and the params useful enough to keep them in, or should they go?"
A current pro is, that they would be able to show a malfunction of utils.build_endpoint, but in any other case they seem to just duplicate the output of raw_response.request.url with less information.

[initBasti]

commit: 79f4c91

[elcolumbio]

That's sounds good, especially when it's only for information purposes. I am no longer on the plentymarkets project.
But i do have a question, i will post in antother issue.
So for computational validation and testing purposes its nice to have python data structures.