Add direct-connect multiplayer foundation

network/connection_endpoint.gd

@@ -0,0 +1,12 @@
+class_name ConnectionEndpoint
+extends RefCounted
+
+var host: String = ""
+var port: int = 7777
+var normalized_display: String = ""
+var original_display: String = ""
+var error_message: String = ""
+
+
+func is_valid() -> bool:
+	return error_message.is_empty() and not host.is_empty() and port in range(1, 65536)