[B] Improve functionality of white-list command - Fixes BUKKIT-5358

Notice: The ticket report is filed as "Bug" instead of "Improvement", my mistake.

**The Issue:**
There is no way to check if a white list is enabled or disabled via command.

**Justification for this PR:**
This PR can provide peace of mind, if the server is white listed for an extended period of time, and the server owner may not know if the white list is still in place.

**JIRA Ticket:**
https://bukkit.atlassian.net/browse/BUKKIT-5358

**Testing Material**
Compiled changes from local fork and tested.

Associated Bukkit Ticket: Coming soon