Add IPv6 support to CRC

[elvgarrui]

Component

None

Is your enhancement related to a problem? Please describe

Currently, CRC only supports IPv4. There are situations where setting up IPv6 environments might be needed.
Single Node Openshift is a different, downstream approach that does support IPv6 configuration. But this cannot be freely used for community efforts or testing gates within different projects like OpenStack RDO, or for creating quick scenarios for developers that need to interact with kubernetes and/or openshift using IPv6.

Describe the solution you'd like

Be able to configure and access CRC using IPv6 addresses.

Describe alternatives you've considered

No response

Additional context

No response

[cfergeau]

gvisor-tap-vsock (the usermode networking stack we are using) does not support ipv6 for now containers/gvisor-tap-vsock#59
When using the system networking stack, there are probably several ipv4 assumptions in crc codebase.

[gbraad]

where setting up IPv6 environments might be needed.

This is currently low priority as mostly people use this in small scale setups, and otherwise it is possible to use a (reverse)proxy (or overlay network) that understands IPv6