[ProjectExport] Fix download file name and errors

[imnasnainaec]

Fixes #3323

Also fixes issue where the downloaded .zip file is supposed to have a file name generated from the project name (#2115) but it didn't.

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This change is 

[codecov]

Codecov Report

Attention: Patch coverage is 21.05263% with 15 lines in your changes missing coverage. Please review.

Project coverage is 74.43%. Comparing base (5a4d614) to head (ed937c6).
Report is 21 commits behind head on master.

Files with missing lines	Patch %	Lines
src/components/ProjectExport/DownloadButton.tsx	21.05%	12 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3622      +/-   ##
==========================================
- Coverage   74.45%   74.43%   -0.03%     
==========================================
  Files         284      284              
  Lines       11048    11054       +6     
  Branches     1354     1356       +2     
==========================================
+ Hits         8226     8228       +2     
- Misses       2431     2434       +3     
- Partials      391      392       +1     

Flag	Coverage Δ
backend	83.88% <ø> (ø)
frontend	66.13% <21.05%> (-0.04%)	⬇️

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[jasonleenaylor]

Reviewed 1 of 1 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @imnasnainaec)