[Fixes #9511] extrapolate FileUploadSizeLimit and UploadParallelismLi…

[mattiagiupponi]

…mit limit from upload form

ref #9511

Checklist

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[codecov]

Codecov Report

Merging #9528 (c25d288) into master (8a22df3) will increase coverage by 0.00%.
The diff coverage is 89.36%.

@@           Coverage Diff           @@
##           master    #9528   +/-   ##
=======================================
  Coverage   61.03%   61.03%           
=======================================
  Files         813      813           
  Lines       49881    49886    +5     
  Branches     7655     7656    +1     
=======================================
+ Hits        30443    30448    +5     
  Misses      17784    17784           
  Partials     1654     1654