Display IPv6 addresses in container details and networks views

[xmirakulix]

This PR has two parts:

• the Container Details view now shows a containers IPv6 address of each network it is connected to, if present

• the Network view now shows all subnets with their gateways within a network (thus including IPv6 subnets)

I did not find other relevant places to add v6 support, but if you show me, I'd be happy to add support there too.

[moncho]

Nice, thanks!! Could you please sign the commit so I can merge? https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits.

And I cannot think of other relevant places.

[xmirakulix]

Done, should be fine ✅