升级Vue3，iView替换ElementPlus

- 删除babel配置、更新依赖与入口初始化
- 全量替换UI组件、样式适配，新增迁移文档与标签/过滤器自动化替换脚本

im/src/icons/index.js

@@ -1,9 +1,10 @@
-import Vue from 'vue';
-import SvgIcon from '@/components/svg-icon'; // svg component
+import SvgIcon from "@/components/svg-icon";
 
-// register globally
-Vue.component('svg-icon', SvgIcon);
+export function registerIcons(app) {
+  app.component("svg-icon", SvgIcon);
 
-const req = require.context('./svg', false, /\.svg$/);
-const requireAll = requireContext => requireContext.keys().map(requireContext);
-requireAll(req);
+  const req = require.context("./svg", false, /\.svg$/);
+  const requireAll = (requireContext) =>
+    requireContext.keys().map(requireContext);
+  requireAll(req);
+}