watchtower/conf: abstract address normalizer to prevent import cycle

watchtower/interface.go

@@ -1,6 +1,8 @@
 package watchtower
 
 import (
+	"net"
+
 	"github.com/lightningnetwork/lnd/watchtower/lookout"
 	"github.com/lightningnetwork/lnd/watchtower/wtserver"
 )
@@ -12,3 +14,8 @@ type DB interface {
 	lookout.DB
 	wtserver.DB
 }
+
+// AddressNormalizer is a function signature that allows the tower to resolve
+// TCP addresses on clear or onion networks.
+type AddressNormalizer func(addrs []string, defaultPort string,
+	resolver func(string, string) (*net.TCPAddr, error)) ([]net.Addr, error)