Fix registering kanalen

[SonnyBA]

Recently introduced changes caused kanalen not to be registered as the used APIClient now only returns Response objects instead of parsed response data, done previously through the zds_client.client.Client (link).

These changes add the missing parsing that should be done of the responses.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 98.29060% with 2 lines in your changes missing coverage. Please review.

Project coverage is 91.76%. Comparing base (aa73035) to head (f6e69a7).
Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
...api_common/management/commands/register_kanalen.py	93.93%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #17      +/-   ##
==========================================
+ Coverage   90.19%   91.76%   +1.56%     
==========================================
  Files          29       31       +2     
  Lines         602      753     +151     
==========================================
+ Hits          543      691     +148     
- Misses         59       62       +3     

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[annashamray]

Just minor remarks

[annashamray]

I think the commit hash is a little extensive, the issue number should be enough

[SonnyBA]

There was no issue created for this but I removed the commit hash

[annashamray]

Looks good