This PR changes the protocol and adds support for DNS subdomains, now
when a DNS resource is added all its subdomains are automatically
tunneled too. Later we will add support for `*.domain` or `?.domain` but
currently there is an Apple split tunnel implementation limitation which
is too labor-intensive to fix right away.
Fixes#2661
Co-authored-by: Andrew Dryga <andrew@dryga.com>