fix(api): use Unstructured to return raw response

[hiddeco]

Fixes: #1899

This pull request ensures that the raw object data returned by the Kargo API matches the data from the Kubernetes API server. Which, unlike the JSON and YAML serializers, purges empty structures.

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[codecov]

Codecov Report

Attention: Patch coverage is 78.50467% with 23 lines in your changes are missing coverage. Please review.

Project coverage is 46.84%. Comparing base (14522e0) to head (8ac4236).

❗ Current head 8ac4236 differs from pull request most recent head 418bf14. Consider uploading reports for the commit 418bf14 to get more accurate results

Files	Patch %	Lines
internal/api/get_analysistemplate_v1alpha1.go	62.96%	6 Missing and 4 partials ⚠️
internal/api/get_freight_v1alpha1.go	86.79%	4 Missing and 3 partials ⚠️
internal/api/get_analysisrun_v1alpha1.go	77.77%	3 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1903      +/-   ##
==========================================
+ Coverage   46.74%   46.84%   +0.09%     
==========================================
  Files         220      220              
  Lines       14411    14464      +53     
==========================================
+ Hits         6737     6776      +39     
- Misses       7374     7382       +8     
- Partials      300      306       +6     

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[devholic]

LGTM 👍

[jessesuen]

Strange that this technique is necessary. Do you know why Kubernetes API doesn't suffer the same problem given that the authentication field is not a pointer?

[hiddeco]

@jessesuen I searched hard and looked at the Kubernetes SIG YAML library and the serializers in API machinery but could not figure out what causes the API to drop the empty objects. If I happen to run into the answer, I will revise what I introduced here.