Add tests for IPv6 security groups

[Milena-Encheva]

Are you submitting this PR against the develop branch?

The PR is submitted to develop.

What is this change about?

As we implement new security from for IPv6, we need to add the corresponding tests. In order ipv6 security groups to be tested - include_security_group and include_ipv6 must be set to true.

What version of cf-deployment have you run this cf-acceptance-test change against?

v50.2.0

Please check all that apply for this PR:

• [X] introduces a new test --- Are you sure everyone should be running this test?
• [ ] changes an existing test
• [ ] requires an update to a CATs integration-config

Did you update the README as appropriate for this change?

• [ ] YES
• [ ] N/A

If you are introducing a new acceptance test, what is your rationale for including it CATs rather than your own acceptance test suite?

CATs should validate common operator workflows. CATs is not a regression test suite. CATs is run by every component team to validate their releases before promotion.

How many more (or fewer) seconds of runtime will this change introduce to CATs?

What is the level of urgency for publishing this change?

• [ ] Urgent - unblocks current or future work
• [X] Slightly Less than Urgent

Tag your pair, your PM, and/or team!

@oliver-heinrich