Allow a second import that overwrites the frontier

[imnasnainaec]

First upload on QA:

First upload with this PR:

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Second upload on QA:

Second upload with this PR:

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This change is 

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 16 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.19%. Comparing base (e082cf9) to head (02eabcf).

Files with missing lines	Patch %	Lines
src/components/ProjectSettings/ProjectImport.tsx	35.71%	9 Missing ⚠️
Backend/Controllers/LiftController.cs	61.11%	5 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3917      +/-   ##
==========================================
- Coverage   74.28%   74.19%   -0.09%     
==========================================
  Files         292      292              
  Lines       10628    10639      +11     
  Branches     1342     1344       +2     
==========================================
- Hits         7895     7894       -1     
- Misses       2352     2363      +11     
- Partials      381      382       +1     

Flag	Coverage Δ
backend	85.37% <61.11%> (-0.12%)	⬇️
frontend	65.82% <35.71%> (-0.07%)	⬇️

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