feat(search): add new event click-input (#4357)

* Update index.wxml

* Update index.ts

packages/search/index.ts

@@ -83,5 +83,9 @@ VantComponent({
     onClear(event: WechatMiniprogram.CustomEvent) {
       this.$emit('clear', event.detail);
     },
+
+    onClickInput: function (event) {
+      this.$emit('click-input', event.detail);
+    },    
   },
 });

packages/search/index.wxml

@@ -32,6 +32,7 @@
       bind:change="onChange"
       bind:confirm="onSearch"
       bind:clear="onClear"
+      bind:click-input="onClickInput"
     >
       <slot wx:if="{{ useLeftIconSlot }}" name="left-icon" slot="left-icon" />
       <slot wx:if="{{ useRightIconSlot }}" name="right-icon" slot="right-icon" />