Allow different process versions to share the same table

The goal here is to allow different runtimes running different versions of the same processes to share the same Kogito runtime table. 

The persistence mechanism would need to look into the process version defined in the bpmn model to restrict the runtime to only load processes that match with the exact same version.

That would be implemented as a column discriminator in the database, where the version is a String that needs to match the same one specified in the BPMN2 model. No special handling on versions is expected at this point.