Ensure clean workspace on each DSS instance in interoperability scenarios

[BenjaminPelletier]

Is your feature request related to a problem? Please describe.
When a DSS interoperability scenario (e.g., ASTM SCD DSS: Subscription and entity interaction) is run with functional but not-successfully-pooled DSS instances, usually only the "primary" DSS instance for that scenario has its workspace cleaned. When DSS instances are pooled correctly, this is sufficient as there is only one DAR and that DAR is cleaned. However, when DSS instances are not pooled correctly, cleaning instance 1 may not ensure a clean workspace in instance 2. Therefore, a failure due to a dirty workspace in instance 2 may be incorrectly labeled as failure to perform basic DSS functions when actually the problem is that the DSS instances are not pooled correctly.

Describe the solution you'd like
While I don't think each DSS instance needs as thorough of a cleaning as the primary instance (since that thorough cleaning procedure will be performed on the DSS instance when it is the primary instance), it seems like we should ensure the entities to be used in the scenario are absent from each DSS instance individually during the "ensure clean workspace" phase.

The "ensure clean workspace" step should probably be split into two steps: "ensure clean workspace on primary DSS instance" and "ensure clean workspace on other DSS instances". In that second step, detecting the presence of any entity deleted in the first step should trigger a check failure related to pooling which should end the scenario.

Describe alternatives you've considered
This is not the only possible solution, but I think it is the simplest one.