fix: Node Issues (#2498)

- Allow adding new nodes without port
- Replace default port number for empty string when there's no port added

lib/core/node_port_validator.dart

@@ -4,8 +4,10 @@ import 'package:cake_wallet/core/validator.dart';
 class NodePortValidator extends TextValidator {
   NodePortValidator()
       : super(
-            errorMessage: S.current.error_text_node_port,
-            minLength: 0,
-            maxLength: 5,
-            pattern: '^[0-9]');
+          errorMessage: S.current.error_text_node_port,
+          minLength: 0,
+          maxLength: 5,
+          pattern: '^[0-9]',
+          isAutovalidate: true,
+        );
 }

lib/src/screens/nodes/widgets/node_form.dart

@@ -19,7 +19,10 @@ class NodeForm extends StatelessWidget {
     this.type,
   })  : _addressController = TextEditingController(text: editingNode?.uri.host.toString()),
         _pathController = TextEditingController(text: editingNode?.path.toString()),
-        _portController = TextEditingController(text: editingNode?.uri.port.toString()),
+        _portController = TextEditingController(
+            text: (editingNode != null && editingNode.uri.hasPort)
+                ? editingNode.uri.port.toString()
+                : ''),
         _loginController = TextEditingController(text: editingNode?.login),
         _passwordController = TextEditingController(text: editingNode?.password),
         _socksAddressController = TextEditingController(text: editingNode?.socksProxyAddress) {
@@ -27,7 +30,7 @@ class NodeForm extends StatelessWidget {
       nodeViewModel
         ..setAddress((editingNode!.uri.host.toString()))
         ..setPath((editingNode!.path.toString()))
-        ..setPort((editingNode!.uri.port.toString()))
+        ..setPort((editingNode!.uri.hasPort ? editingNode!.uri.port.toString() : ''))
         ..setPassword((editingNode!.password ?? ''))
         ..setLogin((editingNode!.login ?? ''))
         ..setSSL((editingNode!.isSSL))

lib/view_model/node_list/node_create_or_edit_view_model.dart

@@ -71,8 +71,7 @@ abstract class NodeCreateOrEditViewModelBase with Store {
 
   @computed
   bool get isReady =>
-      (address.isNotEmpty && port.isNotEmpty) ||
-      _walletType == WalletType.decred; // Allow an empty address.
+      (address.isNotEmpty) || _walletType == WalletType.decred; // Allow an empty address.
 
   bool get hasAuthCredentials =>
       _walletType == WalletType.monero || _walletType == WalletType.wownero || _walletType == WalletType.haven;