A process_class defined at job level has precedence before job chain level

Current Situation

• A job chain can be configured to use a specific process class for subsequent job nodes. This enables a more flexible configuration than assigning the process class to a specific job that would be used for all jobs chains.
• Precedence of process class assignments in decreasing sequence:
  1. order
     • the assignment of a process class is not in scope of this feature
     • the assginment of a remote JobScheduler instance is supported
  2. job chain
  3. job

see JS-1301

Desired Behaviour

• A job chain can be configured to use a specific process class for subsequent job nodes.
• Precedence of process class assignments in decreasing sequence:
  1. order
     • the assignment of a process class is not in scope of this feature
     • the assginment of a remote JobScheduler instance is supported
  2. job
  3. job chain

This changes the order of precedence defined in JS-1301.