PCU: add IPv6 support for SNS

With PCUIF 10 the remote can be IPv4 or IPv6.
Add all missing parts including SNS IPv6 elements,
the support to omit IPv4 elements and a PCU_Tests_SNSv6.cfg
configuration to run all tests with IPv6

Change-Id: I43d64caca600fff78f3fbbb3e8179f447f235d46
4 files changed