Add support for IPv6 targets to network-latency and network-packet-loss faults

[amogh09]

Summary

This change extends support for network-latency and network-packet-loss faults to IPv6 targets. Today only IPv4 targets are accepted by these APIs but after this change IPv6 targets are accepted as well.

Implementation details

Request validation is changed for the APIs so that they accept IPv6 and IPv6 CIDR Sources (targets) and SourcesToFilter (protected targets).

tc commands used for network-latency and network-packet-loss faults are updated so that -

1. Protocol specified in the filter add commands is all instead of ip. all applies to all protocols whereas ip applies to IPv4 only.
2. Matcher specified in the filter add commands uses ip selector for IPv4 targets and ip6 for IPv6 targets.

Testing

Performed a variety of manual tests including the cases below.

1. IPv6 target only with and without a target to filter (protect).
2. IPv6 CIDR target only with and without a target to filter (protect).
3. IPv4 and IPv6 targets with no targets to filter.
4. IPv4 and IPv6 targets with an IPv4 target protected.
5. IPv4 and IPv6 targets with an IPv6 target protected.

In call cases above, the faults worked as expected. There was no network degradation for traffic to filtered targets but there was expected network degradation for traffic to destinations matching the targets.

New tests cover the changes: yes

Description for the changelog

Enhancement: Add support for IPv6 targets to network-latency and network-packet-loss faults

Additional Information

Does this PR include breaking model changes? If so, Have you added transformation functions?

No

Does this PR include the addition of new environment variables in the README?

No

Licensing

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.