🐛 Fix custom filterDropdown trigger sorter

close #14238

components/table/__tests__/__snapshots__/Table.filter.test.js.snap

@@ -31,7 +31,9 @@ exports[`Table.filter renders custom content correctly 1`] = `
   <div
     class="ant-dropdown  ant-dropdown-placement-bottomRight  ant-dropdown-hidden"
   >
-    <div>
+    <div
+      class="ant-table-filter-dropdown"
+    >
       <div
         class="custom-filter-dropdown"
       >

components/table/demo/custom-filter-panel.md

@@ -50,7 +50,7 @@ class App extends React.Component {
     filterDropdown: ({
       setSelectedKeys, selectedKeys, confirm, clearFilters,
     }) => (
-      <div className="custom-filter-dropdown">
+      <div style={{ padding: 8 }}>
         <Input
           ref={node => { this.searchInput = node; }}
           placeholder={`Search ${dataIndex}`}
@@ -129,12 +129,3 @@ class App extends React.Component {
 
 ReactDOM.render(<App />, mountNode);
 ````
-
-````css
-.custom-filter-dropdown {
-  padding: 8px;
-  border-radius: 4px;
-  background: #fff;
-  box-shadow: 0 2px 8px rgba(0, 0, 0, .15);
-}
-````

components/table/filterDropdown.tsx

@@ -247,7 +247,9 @@ export default class FilterMenu<T> extends React.Component<FilterMenuProps<T>, F
     }
 
     const menus = filterDropdown ? (
-      <FilterDropdownMenuWrapper>{filterDropdown}</FilterDropdownMenuWrapper>
+      <FilterDropdownMenuWrapper className={`${prefixCls}-dropdown`}>
+        {filterDropdown}
+      </FilterDropdownMenuWrapper>
     ) : (
       <FilterDropdownMenuWrapper className={`${prefixCls}-dropdown`}>
         <Menu