Fixes#4139
This builds the local (for the node) `Affiliate` structure which
describes node for the cluster discovery. Dependending on the
configuration, KubeSpan information might be included as well.
`NodeAddresses` were updated to hold CIDRs instead of simple IPs.
The `Affiliate` will be pushed to the registries, while `Affiliate`s for
other nodes will be fetched back from the registries.
Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>
