[O2B-1544] Fix envs query builder and add test

[isaachilly]

Replaced two-query pattern with a single queryBuilder in GetAllEnvironmentsUseCase. Two were unnecessary and pagination was implemented incorrectly (applied too early).

Added a test to verify that total count reflects all matching environments and that paginated filtered results are correct across multiple pages.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 45.61%. Comparing base (55062b6) to head (02d7f53).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2096      +/-   ##
==========================================
- Coverage   45.63%   45.61%   -0.02%     
==========================================
  Files        1039     1039              
  Lines       17324    17318       -6     
  Branches     3148     3147       -1     
==========================================
- Hits         7905     7899       -6     
  Misses       9419     9419              

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[NarrowsProjects]

Minor code stylisation change request