refactor(platform): extract platform detection into separate module

移除各文件中重复的平台检测代码，统一封装到platform.js模块，添加缓存优化，支持多端平台检测、app_type和显示名称获取等能力，简化后续平台相关代码维护

common/js/util.js

@@ -1,6 +1,7 @@
 import Config from './config.js'
 import store from '@/store/index.js'
 import Http from './http.js'
+import Platform from './platform.js'
 import {
 	Weixin
 } from 'common/js/wx-jssdk.js';
@@ -381,35 +382,7 @@ export default {
 	 * @param url
 	 */
 	upload: function (num, params, callback, url) {
-		// #ifdef H5
-		var app_type = this.isWeiXin() ? 'wechat' : 'h5';
-		var app_type_name = this.isWeiXin() ? '微信公众号' : 'H5';
-		// #endif
-
-		// #ifdef MP-WEIXIN
-		var app_type = 'weapp';
-		var app_type_name = '微信小程序';
-		// #endif
-
-		// #ifdef MP-ALIPAY
-		var app_type = 'aliapp';
-		var app_type_name = '支付宝小程序';
-		// #endif
-
-		// #ifdef MP-BAIDU
-		var app_type = 'baiduapp';
-		var app_type_name = '百度小程序';
-		// #endif
-
-		// #ifdef MP-TOUTIAO
-		var app_type = 'MP-TOUTIAO';
-		var app_type_name = '头条小程序';
-		// #endif
-
-		// #ifdef MP-QQ
-		var app_type = 'MP-QQ';
-		var app_type_name = 'QQ小程序';
-		// #endif
+		const { app_type, app_type_name } = Platform.getPlatformInfo();
 		var data = {
 			token: store.state.token,
 			app_type: app_type,