[backend] improve report cascade delete algorithm to prevent Already deleted error (#6874)

[JeremyCloarec]

Proposed changes

• When cascade deleting in a report, we now check that relationships from or to are not already included in the list of elements to delete. If that is the case, we don't need to delete this relationship because it will be deleted during the deletion of the source element

Related issues

• Already deleted error when cascade deleting in report #6874

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality
• I wrote test cases for the relevant uses case (coverage and e2e)
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality

Further comments

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 8 lines in your changes are missing coverage. Please review.

Project coverage is 67.49%. Comparing base (4ab5d2a) to head (74db82e).
Report is 3 commits behind head on master.

Files	Patch %	Lines
...ncti-platform/opencti-graphql/src/domain/report.js	0.00%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6967      +/-   ##
==========================================
+ Coverage   67.41%   67.49%   +0.07%     
==========================================
  Files         561      561              
  Lines       68510    68540      +30     
  Branches     5712     5808      +96     
==========================================
+ Hits        46186    46259      +73     
+ Misses      22324    22281      -43     

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