VRRP IPv6

This pull request includes all actions, templates and methods to configure VRRP IPv6. 

- VRRPGroup includes new attribute, required for VRRP IPv6: virtuaLinkAddress

- Commands are valids for both ips. IPv6 required new command to update virtualLinkAddress.

- Actions choose IPv4 or IPv6 template according to VRRPProtocolEndpoint ProtocolIFType.

- Tests for templates, actions and capability.