Add functions for retrieving latest versions from various services

[ananace]

These are being upstreamed from code that's running internally at Linköping University, in cases like these; (with our internal identifiers replaced with these extlib names)

# class profiles::kube::node(
#   $release => 1.33
#   $etcd_release => 3.5

class { 'k8s':
  version      => extlib::version_latest_endoflife('kubernetes', $release),
  etcd_version => extlib::version_latest_endoflife('etcd', $etcd_release),
# ...
}

Pull Request (PR) description

Adds functions for querying various services to retrieve the latest versions of projects/products.

This Pull Request (PR) fixes the following issues