wip: add easy_localization.

app/lib/extensions/context_extension.dart

@@ -0,0 +1,8 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+
+extension ContextExtension on BuildContext {
+  ThemeData get t => Theme.of(this);
+
+  NavigatorState get n => Navigator.of(this);
+}

app/lib/extensions/string_extension.dart

@@ -0,0 +1,3 @@
+extension StringNotNull on String? {
+  bool get notNull => this != null && this != '';
+}