Extend armageddon generate to support known certs and app orgs

[tock-ibm]

In order to implement testing with known certs and signatures with cert-id (#638 ), we need to extend armageddon generate to create

1. an app org that is different then the ordering orgs (different mspid)
2. some users for said app-org
3. add the users to the known cert of said app-org.

Step 3 should be configurable in order to allow testing with and without known-certs