[backend] When adding a relationship to a container assigned to someone, notification shows unknown (#8684)

[ValentinBouzinFiligran]

Proposed changes

• relationships condition added on generateUpdateMessage

Related issues

• When adding a relationship to a container assigned to someone, notification shows "unknown"  #8684

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

All modified and coverable lines are covered by tests ✅

Project coverage is 66.25%. Comparing base (0dc1991) to head (5f7f77f).
Report is 5 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #9014      +/-   ##
==========================================
- Coverage   66.28%   66.25%   -0.04%     
==========================================
  Files         597      597              
  Lines       61098    61163      +65     
  Branches     6288     6291       +3     
==========================================
+ Hits        40501    40521      +20     
- Misses      20597    20642      +45     

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[Archidoit]

The relationship representative is not always correct.
Exemple, if I create this relationship :

I get in the history :

--> The representative of Observed Data is not correct

[Archidoit]

If the representative is too long, it is not fully displayed in the tooltip :

[Archidoit]

If the representative is too long, it is not fully displayed in the tooltip :

--> issue created for this #9021