Fix tests

Author: petrnymsa

glade_forms/test/devtools_extension_test.dart

@@ -4,6 +4,8 @@ import 'package:glade_forms/glade_forms.dart';
 import 'package:test/test.dart';
 
 void main() {
+  setUp(GladeForms.initialize);
+
   test('GladeInput with non-nullable type', () {
     final input = GladeInput<int>.create(
       validator: (v) => v.build(),

glade_forms/test/glade_input_test.dart

@@ -42,6 +42,8 @@ class _ModeWithDependencies extends GladeModel {
 }
 
 void main() {
+  setUp(GladeForms.initialize);
+
   test('When updating [a] onDependencyChange is called for a', () {
     final model = _ModeWithDependencies();
 

glade_forms/test/model/glade_model_test.dart

@@ -55,6 +55,8 @@ class _ModeWithDependencies extends GladeModel {
 }
 
 void main() {
+  setUp(GladeForms.initialize);
+
   test('When updating [a] listener is called', () {
     final model = _Model();
     var listenerCount = 0;