[plotterparameter] dont cache default-valued fields

Avoids ever caching/saving default-valued fields in the
plotterparameter editor
3 jobs for 213-incremental-plotterparameters in 23 minutes and 54 seconds (queued for 1 second)
Status Name Job ID Coverage
  Build
passed build_linux_36 #166787
docker

00:15:58

passed build_macosx_36 #166788
macosx

00:08:14

 
  Browser Tests
passed browser_test #166789
docker

00:07:56