feat(variable-modal): implement variable value editor modal and associated tests

[RemiBonnet]

Summary

Add value editor for variable and variable as file creation flows

• https://qovery.slack.com/archives/C0AML0VDUV8/p1774543889916119
• https://qovery.slack.com/archives/C02P2JB4SEM/p1774544038831689

Screenshots / Recordings

https://www.loom.com/share/d36068304f5240f3a69cd61be205bb0a

Testing

• Changes tested locally in the relevant Console's pages and Storybooks
• yarn test or yarn test -u (if you need to regenerate snapshots)
• yarn format
• yarn lint

PR Checklist

• I followed naming, styling, and TypeScript rules (see .cursor/rules)
• I performed a self-review (diff inspected, dead code removed)
• I titled the PR using Conventional Commits with a scope when possible (e.g. feat(service): add new Terraform service) - required for semantic-release
• I only kept necessary comments, written in English (watch for useless AI comments)
• I involved a designer to validate UI changes if I am not a designer
• I covered new business logic with tests (unit)
• I confirmed CI is green (Codecov red can be accepted)
• I reviewed and executed locally any AI-assisted code

[codecov]

Codecov Report

❌ Patch coverage is 51.42857% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 45.01%. Comparing base (cf769de) to head (797d999).
⚠️ Report is 2 commits behind head on new-navigation.

Files with missing lines	Patch %	Lines
...te-variable-modal/create-update-variable-modal.tsx	36.84%	7 Missing and 5 partials ⚠️
...value-editor-modal/variable-value-editor-modal.tsx	68.75%	2 Missing and 3 partials ⚠️

Additional details and impacted files

@@                Coverage Diff                 @@
##           new-navigation    #2585      +/-   ##
==================================================
- Coverage           45.81%   45.01%   -0.80%     
==================================================
  Files                1129     1062      -67     
  Lines               22959    21898    -1061     
  Branches             6719     6425     -294     
==================================================
- Hits                10518     9858     -660     
+ Misses              10531    10272     -259     
+ Partials             1910     1768     -142     

Flag	Coverage Δ
unittests	45.01% <51.42%> (-0.80%)	⬇️

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[rmnbrd]

LGTM, well done 👍