refactor(theme&ui): improve theme switching and navigation styling

lib/product/services/theme_services.dart

@@ -0,0 +1,33 @@
+import 'package:flutter/material.dart';
+
+import '../cache/local_manager.dart';
+import '../constant/enums/app_theme_enums.dart';
+import '../constant/enums/local_keys_enums.dart';
+import '../theme/app_theme_dark.dart';
+import '../theme/app_theme_light.dart';
+
+class ThemeServices{
+
+  ThemeData _currentTheme(String theme) {
+    if (theme == AppThemes.LIGHT.name) {
+      return AppThemeLight.instance.theme;
+    } else if (theme == AppThemes.DARK.name) {
+      return AppThemeDark.instance.theme;
+    } else {
+      return AppThemeLight.instance.theme;
+    }
+  }
+
+  Future<ThemeData> getTheme() async {
+    await LocaleManager.prefrencesInit();
+    String theme = LocaleManager.instance.getStringValue(PreferencesKeys.THEME);
+    return _currentTheme(theme);
+  }
+
+  Future<ThemeData> changeTheme(String theme) async {
+    await LocaleManager.prefrencesInit();
+    LocaleManager.instance
+        .setStringValue(PreferencesKeys.THEME, theme);
+    return _currentTheme(theme);
+  }
+}