fix[Select|Cascader]: select multiple error & cascader error in ssr mode (#7377)

* docs: updating the `dropdownRender` description and jumps in the FAQ for Select

* fix: fix  select error in multiple mode

* fix: fix cascader select error in ssr mode

components/vc-cascader/OptionList/Column.tsx

@@ -4,6 +4,7 @@ import type { DefaultOptionType, SingleValueType } from '../Cascader';
 import { SEARCH_MARK } from '../hooks/useSearchOptions';
 import type { Key } from '../../_util/type';
 import { useInjectCascader } from '../context';
+import { cloneVNode } from 'vue';
 export const FIX_LABEL = '__cascader_fix_label__';
 export interface ColumnProps {
   prefixCls: string;
@@ -151,10 +152,10 @@ export default function Column({
             )}
             <div class={`${menuItemPrefixCls}-content`}>{label}</div>
             {!isLoading && expandIcon && !isMergedLeaf && (
-              <div class={`${menuItemPrefixCls}-expand-icon`}>{expandIcon}</div>
+              <div class={`${menuItemPrefixCls}-expand-icon`}>{cloneVNode(expandIcon)}</div>
             )}
             {isLoading && loadingIcon && (
-              <div class={`${menuItemPrefixCls}-loading-icon`}>{loadingIcon}</div>
+              <div class={`${menuItemPrefixCls}-loading-icon`}>{cloneVNode(loadingIcon)}</div>
             )}
           </li>
         );

components/vc-select/TransBtn.tsx

@@ -1,4 +1,4 @@
-import type { FunctionalComponent, PropType } from 'vue';
+import { cloneVNode, type FunctionalComponent, type PropType } from 'vue';
 import type { MouseEventHandler } from '../_util/EventInterface';
 import type { VueNode } from '../_util/type';
 import PropTypes from '../_util/vue-types';
@@ -23,7 +23,7 @@ const TransBtn: TransBtnType = (props, { slots }) => {
   if (typeof customizeIcon === 'function') {
     icon = customizeIcon(customizeIconProps);
   } else {
-    icon = customizeIcon;
+    icon = cloneVNode(customizeIcon);
   }
 
   return (