In previous implementation NeoFS CLI app used `network.Address.HostAddr`
as a server URI, which caused scheme loss since host address doesn't
contain it.
Rename `HostAddr` to `URIAddr` and make it to return URI address with
`grpcs` scheme if TLS is enabled. Make `TLSEnabled` unexported since it
was used to provide default `tls.Config` only (it is used by default in
SDK).
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
