lnwire: update NodeAnnouncement to handle multiple addresses

This commit modifies address handling in the NodeAnnouncement struct,
switching from net.TCPAddr to []net.Addr. This enables more flexible
address handling with multiple types and multiple addresses for each
node. This commit addresses the first part of issue #131 .

channeldb/error.go

@@ -73,4 +73,8 @@ var (
 
 	// ErrNodeAliasNotFound is returned when alias for node can't be found.
 	ErrNodeAliasNotFound = fmt.Errorf("alias for node not found")
+
+	// ErrUnknownAddressType is returned when a node's addressType is not
+	// an expected value.
+	ErrUnknownAddressType = fmt.Errorf("address type cannot be resolved")
 )