refactor(many files): 页面部分的文件结构调整

1.views 文件夹里面分类，页面相关文件;2.公共组件全部放在components里;3.创建resources文件夹放置资源dart文件4.修改二级菜单文字大小

BREAKING CHANGE: 重构，建议删除本地db,再编译

lib/widgets/elements/Form/Button/RawMaterialButton/index.dart

@@ -7,7 +7,7 @@
  * target: RawMaterialButton 的示例
  * 对应文档地址:https://docs.flutter.io/flutter/material/RawMaterialButton-class.html
  */
-import '../../../../../common/widget_demo.dart';
+import 'package:flutter_go/components/widget_demo.dart';
 import 'dart:math';
 import 'package:flutter/material.dart';