Add support for dual stack clusters

[UXabre]

Adds support for dual stack clusters

resolves: #832

[UXabre]

Hi, anything needed from my end to push this forward? Really don't want to sound pushy in any way, just curious what my best course of action is, even if that action is inaction and simple patience on my end :-)

[M0NsTeRRR]

Looking for this feature too, as I see on other PR @UXabre maybe you can ask for a review of hashicorp team to push it further ?

[UXabre]

I've updated this PR to resolve the conflict, if somebody could review this? :-)

EDIT: Also added unit tests

[UXabre]

@hsimon-hashicorp Maybe you can help me with this PR? As I see nobody has reviewed it yet and perhaps you are my last hope :-) (sorry for spamming)

[heatherezell]

@hsimon-hashicorp Maybe you can help me with this PR? As I see nobody has reviewed it yet and perhaps you are my last hope :-) (sorry for spamming)

Not spam at all, this is my job. :) I've pinged our engineers to see if one can help with a review. Thanks!

[belyaev-dev]

joining waitlist :)

[tvoran]

Thanks, left a couple thoughts. And should we set these parameters in templates/server-headless-service.yaml as well?

[hashicorp-cla]

All committers have signed the CLA.

[UXabre]

Thanks, left a couple thoughts. And should we set these parameters in templates/server-headless-service.yaml as well?

I've also added this to headless :-)

[UXabre]

All changes have been applied and I've rebased with main just to be on the safe side :-)

[tvoran]

Thanks!