Improve demo examples/features/standard/security-ldap

The AMQ 7.2 demo at examples/features/standard/security-ldap needs improvements.

First there is no README or any other file that provides any details of the demo.
The doc at https://activemq.apache.org/artemis/docs/latest/examples.html does not mention the security-ldap demo. The other demos are only documented from a high level, without build and run instructions.

Second, I don't believe the files

src/main/resources/activemq/server0/artemis-roles.properties
src/main/resources/activemq/server0/artemis-users.properties

are needed in this demo which is about LDAP based authentication and authorization.
At least it seems the demo runs without these files, despite the output being difficult to understand due to many warnings raised by the in-memory LDAP server.

Third, and more optional, perhaps the output at runtime could be improved. The many warnings from the in-memory LDAP server are very confusing and leave the initial impression that the demo failed completely ...