ignore when required variable was already added to selection

[rowe-stamy]

Added new test where the User from Accounts can have a ProductConfiguration and ProductBookmark
matched by the username field instead of id. The bug fix is to ignore if a required variable was already added.
Closes #6993 (in this specific format)

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[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 72.44%. Comparing base (a869df6) to head (b7252aa).

❗ Current head b7252aa differs from pull request most recent head 2b9debe

Please upload reports for the commit 2b9debe to get more accurate results.

Files	Patch %	Lines
...ing/Pipeline/FieldRequirementsPlannerMiddleware.cs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6995      +/-   ##
==========================================
- Coverage   74.42%   72.44%   -1.98%     
==========================================
  Files        2608     2625      +17     
  Lines      131126   131689     +563     
==========================================
- Hits        97584    95407    -2177     
- Misses      33542    36282    +2740     

Flag	Coverage Δ
unittests	72.44% <0.00%> (-1.98%)	⬇️

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[michaelstaib]

Thanks for creating this PR ... I will soon have a look.

[michaelstaib]

I will get this one in next week .... we have one massive PR that we need to merge first.