feat: modal&drawer support appendToMain and zIndex (#5092)

* feat: modal/drawer support append to main content

* feat: modal zIndex support

* fix: drawer prop define

* chore: type

* fix: modal/drawer position fixed while append to body

* docs: typo

* chore: add full-width drawer in content area

* chore: remove unnecessary class

playground/src/views/examples/vxe-table/basic.vue

@@ -76,6 +76,12 @@ function changeLoading() {
     <template #extra>
       <DocButton path="/components/common-ui/vben-vxe-table" />
     </template>
+    <Modal title="弹窗测试">
+      <p>这是一个弹窗</p>
+    </Modal>
+    <Drawer title="抽屉测试">
+      <p>这是一个抽屉</p>
+    </Drawer>
     <Grid table-title="基础列表" table-title-help="提示">
       <!-- <template #toolbar-actions>
         <Button class="mr-2" type="primary">左侧插槽</Button>