[cherry-pick] fix: increase beego max memory and upload size (#19578)

[stonezdj]

1. Increase the default beego max memory and upload size from 32GB to 128GB.
2. Support customize the two beego configs from env.

(cherry picked from commit 553c85e)

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[wy65701436]

lgtm

[codecov]

Codecov Report

Merging #19670 (916244f) into release-2.8.0 (10286c7) will increase coverage by 0.03%.
The diff coverage is 0.00%.

Additional details and impacted files

@@                Coverage Diff                @@
##           release-2.8.0   #19670      +/-   ##
=================================================
+ Coverage          67.34%   67.37%   +0.03%     
=================================================
  Files                984      984              
  Lines             107090   107094       +4     
  Branches            2671     2671              
=================================================
+ Hits               72122    72158      +36     
+ Misses             31085    31053      -32     
  Partials            3883     3883              

Flag	Coverage Δ
unittests	67.37% <0.00%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/lib/config/systemconfig.go	50.35% <0.00%> (-1.48%)	⬇️

... and 7 files with indirect coverage changes