新增布局PageLayout，优化代码结构

src/components/form/Form.vue

@@ -1,42 +0,0 @@
-<template>
-  <div style="margin: -24px -24px 0px">
-    <page-header :breadcrumb="breadcrumb" :title="title">
-      <div slot="content">{{desc}}</div>
-    </page-header>
-    <div style="margin: 24px 24px 0px">
-      <router-view  ref="page"/>
-    </div>
-  </div>
-</template>
-
-<script>
-import PageHeader from '../page/PageHeader'
-export default {
-  name: 'Form',
-  components: {PageHeader},
-  data () {
-    return {
-      title: '',
-      breadcrumb: [],
-      desc: ''
-    }
-  },
-  mounted () {
-    this.getPageHeaderInfo()
-  },
-  beforeUpdate () {
-    this.getPageHeaderInfo()
-  },
-  methods: {
-    getPageHeaderInfo () {
-      this.title = this.$route.name
-      this.breadcrumb = this.$route.matched
-      this.desc = this.$refs.page.desc
-    }
-  }
-}
-</script>
-
-<style scoped>
-
-</style>