feat(Cascader): title attributes are added to the selected content text by default (#31237)

* update cascader snapshot

* feat(cascader): Add a friendlier title prompt to the label

components/cascader/__tests__/__snapshots__/demo.test.js.snap

@@ -209,6 +209,7 @@ exports[`renders ./components/cascader/demo/default-value.md correctly 1`] = `
 >
   <span
     class="ant-cascader-picker-label"
+    title="Zhejiang / Hangzhou / West Lake"
   >
     Zhejiang / Hangzhou / West Lake
   </span>

components/cascader/__tests__/__snapshots__/index.test.js.snap

@@ -1117,6 +1117,7 @@ exports[`Cascader support controlled mode 1`] = `
 >
   <span
     class="ant-cascader-picker-label"
+    title="Zhejiang / Hangzhou / West Lake"
   >
     Zhejiang / Hangzhou / West Lake
   </span>

components/cascader/index.tsx

@@ -316,7 +316,7 @@ class Cascader extends React.Component<CascaderProps, CascaderState> {
   };
 
   getLabel() {
-    const { options, displayRender = defaultDisplayRender as Function } = this.props;
+    const { options, displayRender = defaultDisplayRender } = this.props;
     const names = getFilledFieldNames(this.props);
     const { value } = this.state;
     const unwrappedValue = Array.isArray(value[0]) ? value[0] : value;
@@ -618,9 +618,15 @@ class Cascader extends React.Component<CascaderProps, CascaderState> {
           inputIcon = <DownOutlined className={arrowCls} />;
         }
 
+        const label = this.getLabel();
         const input: React.ReactElement = children || (
           <span style={style} className={pickerCls}>
-            <span className={`${prefixCls}-picker-label`}>{this.getLabel()}</span>
+            <span
+              className={`${prefixCls}-picker-label`}
+              title={typeof label === 'string' && label ? label : undefined}
+            >
+              {label}
+            </span>
             <Input
               {...inputProps}
               tabIndex={-1}

components/form/__tests__/__snapshots__/demo.test.js.snap

@@ -3321,6 +3321,7 @@ exports[`renders ./components/form/demo/register.md correctly 1`] = `
           >
             <span
               class="ant-cascader-picker-label"
+              title="Zhejiang / Hangzhou / West Lake"
             >
               Zhejiang / Hangzhou / West Lake
             </span>

components/input/__tests__/__snapshots__/demo.test.js.snap

@@ -632,6 +632,7 @@ Array [
   >
     <span
       class="ant-cascader-picker-label"
+      title="Zhejiang / Hangzhou / West Lake"
     >
       Zhejiang / Hangzhou / West Lake
     </span>