Improve build system

[ComLock]

Currently this takes 12 seconds
enonic project gradle clean build deploy -x lint -x test

npx tsc --pretty --skipLibCheck --noEmit 2.93s user 0.18s system 224% cpu 1.383 total
npx webpack --color --stats-error-details 2.89s user 0.31s system 185% cpu 1.728 total
npm run build 6.09s user 0.52s system 341% cpu 1.938 total

These take very little time already, so there might not be much to save here...