RestWorkItemHandler fails with CNFE when using ResultClass attribute in kie-workbench

It is possible to set ResultClass attribute for Rest Work Item.
When the process including this workitem is deployed in kie-workbench, the actual result transformation to POJO fails with CNFE.

This can be solved by adding a 'classLoader' argument to the RestWorkItemHandler definition in the deployment descriptor.

I propose to add this configuration to the descriptor by default, that would mean, that ResultClass could be used out of the box without any further changes.