Add valueConversion renderingOption for auto loading storage data
Create resolver for generic plugins
Support custom plugin props in script node exec/file copiers

* use a conventional project/framework property making for the property
  configs
* Allow renderingOptions to be defined for script plugin config
  properties
* support valueConversion rendering option to load storage values
Allow node attributes as instance scope data for script plugins
Support script-based node execu plugin custom properties for #979