fix: 隐藏菜单时，不移除Popup里的内容 (#1891)

src/packages/__VUE/menuitem/index.scss

@@ -39,7 +39,6 @@
 .nut-menu__pop {
   transition: all 0 ease 0;
   transform: none;
-  overflow: hidden;
 }
 
 .placeholder-element {

src/packages/__VUE/menuitem/index.taro.vue

@@ -1,5 +1,5 @@
 <template>
-  <view :class="classes" v-show="state.showWrapper" style="position: fixed" :style="{ zIndex: state.zIndex }">
+  <view :class="classes" v-show="state.showWrapper" :style="{ zIndex: state.zIndex }">
     <div
       v-show="state.isShowPlaceholderElement"
       @click="handleClickOutside"
@@ -13,13 +13,16 @@
         parent.props.direction === 'down' ? { top: parent.offset.value + 'px' } : { bottom: parent.offset.value + 'px' }
       "
       :overlay-style="
-        parent.props.direction === 'down' ? { top: parent.offset.value + 'px' } : { bottom: parent.offset.value + 'px' }
+        parent.props.direction === 'down'
+          ? { top: parent.offset.value + 'px' }
+          : { bottom: parent.offset.value + 'px', top: 'auto' }
       "
       v-bind="$attrs"
       v-model:visible="state.showPopup"
       :position="parent.props.direction === 'down' ? 'top' : 'bottom'"
       :duration="parent.props.duration"
       pop-class="nut-menu__pop"
+      :destroy-on-close="false"
       :overlay="parent.props.overlay"
       :lockScroll="parent.props.lockScroll"
       @closed="handleClose"

src/packages/__VUE/menuitem/index.vue

@@ -13,14 +13,16 @@
         parent.props.direction === 'down' ? { top: parent.offset.value + 'px' } : { bottom: parent.offset.value + 'px' }
       "
       :overlayStyle="
-        parent.props.direction === 'down' ? { top: parent.offset.value + 'px' } : { bottom: parent.offset.value + 'px' }
+        parent.props.direction === 'down'
+          ? { top: parent.offset.value + 'px' }
+          : { bottom: parent.offset.value + 'px', top: 'auto' }
       "
       v-bind="$attrs"
       v-model:visible="state.showPopup"
       :position="parent.props.direction === 'down' ? 'top' : 'bottom'"
       :duration="parent.props.duration"
       pop-class="nut-menu__pop"
-      overlayClass="nut-menu__overlay"
+      :destroy-on-close="false"
       :overlay="parent.props.overlay"
       @closed="handleClose"
       :lockScroll="parent.props.lockScroll"