[ipv6] Add ipv6 informations at site level (bug 12768)

Based on earlier work from David Loup: https://gitlab.inria.fr/grid5000/reference-repository/-/tree/ipv6_site_info
5 jobs for ipv6_site_info_v2 in 6 minutes and 18 seconds (queued for 1 second)
Status Job ID Name Coverage
  Validate
passed #1002064
grid5000-docker
rubocop

00:00:39

passed #1002065
grid5000-docker
validate-data

00:01:51

 
  Generate
passed #1002066
grid5000-docker
generate-reference-api

00:01:31

 
  Deploy
passed #1002067
grid5000-shell
deploy

00:00:17

passed #1002068
grid5000-docker
rspec

00:02:54