fix(build): docker image build improvements

[garrappachc]

• don't produce type definitions (*.d.ts)
• don't write source maps
• use node user to run the app inside docker

[codecov]

Codecov Report

Merging #924 (33ddc8a) into master (60ae7c3) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #924   +/-   ##
=======================================
  Coverage   93.54%   93.54%           
=======================================
  Files         116      116           
  Lines        2556     2556           
  Branches      267      267           
=======================================
  Hits         2391     2391           
  Misses        164      164           
  Partials        1        1           

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