SqlAGListener: 15 character name limit

Details of the scenario you try and problem that is occurring:

I don't think the resource should decide what naming convention you can use. The 15 character limit should be removed from the resource. As good practice, when you create a SQL Server you also create a DNS hostname (EG BusinessApplication-DB-Prod.contoso.corp) so that when you migrate the database to another server, all you need to do is modify the hostname and not all the applications. Usually these hostnames are longer than 15 characters because you're adding other descriptors such as 'db' and 'prod' in the name. As per Microsoft (https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/create-or-configure-an-availability-group-listener-sql-server - see image below) the maximum length for a DNS name is 63 characters. Only SQL Management Studio limits you to 15 because of the warning mentioned in the screenshot. By manually removing the limit in Set/Get/Test I can create 20 character listener names and they work perfectly providing the first 15 characters are unique. @johlju what are your thoughts?

Edit: typo should -> shouldn't

The DSC configuration that is using the resource (as detailed as possible):

Version of the Operating System, SQL Server and PowerShell the DSC Target Node is running:

Server: Windows 2012 R2 (Update)
SQL Server: 2016 SP1 CU2
Powershell: 5.1

Version of the DSC module you're using, or 'dev' if you're using current dev branch:

dev as of today

Start with the SqlAGListener Set, Get, and Test resource operations and inspect where the 15-character validation is applied. Confirm the behavior against the reported SQL Server 2016 scenario; done means listener names longer than 15 characters are accepted while the documented uniqueness behavior remains valid.