FLUID-5222: build and init func for prefsEditor

Added fluid.prefs.create as a single build and init function for the prefsEditor. Unit tests and demos need to be updated still.
FLUID-5222: Updated manual tests

Updated the manual tests to use fluid.prefs.create function.
FLUID-5222: Fix the unit tests for aux builder since the default namespace for the constructed prefs editor is improved to be a random string.
Merge remote-tracking branch 'cindy/FLUID-5222' into FLUID-5222
Merge branch 'FLUID-5222'

* FLUID-5222:
  FLUID-5222: Fix the unit tests for aux builder since the default namespace for the constructed prefs editor is improved to be a random string.
  FLUID-5222: Updated manual tests
  FLUID-5222: build and init func for prefsEditor