Java Bindings: allow creating a participant user w/o any rights and primary party

[meiersi-da]

What is the problem you want to solve?

Allow creating a participant user w/o any rights and no associated primary party via the Java Bindings. We found this useful in the CN apps, where we use incremental and idempotent code in our Java apps to setup users on the correspnoding participant node.

It's also supported by the Ledger API.

What is the solution you would propose?

Add a variant of this code that does not require providing at least one user right: https://github.com/digital-asset/daml/blob/93604ebba7540a9132b6f3780ad7d4b9f9f98a43/canton/community/bindings-java/src/main/java/com/daml/ledger/javaapi/data/CreateUserRequest.java#L19-L24