Docs: Feedback for Cluster Utilities

Hi, I have some feedback about [this page](https://github.com/hazelcast/imdg-docs/edit/v/3.12/docs/modules/management/pages/cluster-utilities.adoc)

This states:

> Also note that the value of ${PASSWORD} in the following calls is checked only if the security is enabled in Hazelcast IMDG, i.e., if you have Hazelcast IMDG Enterprise Edition.

But it doesn't tell the whole story. If you have an `identity` defined for your `member-authentication` under security, then you need to omit the `${CLUSTERNAME}` and instead use the `identity.username` of the security realm used in the `member-authentication` (`${PASSWORD}` should be the corresponding `identity.password`).

There may be other caveats not listed here. The doc should be clear about what parameters are required and when.