CreateRoleParams displayName is optional, but throws java.lang.NullPointerException

[ComLock]

createRole({
	name: 'roleName'
});

causes

2024-03-27 09:55:49,465 ERROR c.e.xp.portal.impl.main.MainExecutor - Error while executing com.acme.example.tsup Application controller
java.util.concurrent.CompletionException: java.lang.NullPointerException: displayName is required for a role

The documentation is unclear
https://developer.enonic.com/docs/xp/stable/api/lib-auth#createrole

Sidenote:
I appUsers it's not possible to create a role without displayName.
The name is just sanitized displayName.

We have two possible solutions:

1. Make displayName required in the type and documentation
   OR
2. Make it possible to create a role without passing displayName

[alansemenov]

We won't change Java API (for now, at least), so displayName will have to stay required. We have to fix the TS code though, because displayName is currently nullable there (for users and groups as well). Added a separate task for the docs: enonic/doc-xp#523.