[breaking change] Search: 修改原有结构 (#198)

* 修改文档 注释

* [breaking change] change type showcase to simple

* [breaking change] search 组件传入参数更改

* search 文档更改

* [breaking change] delete type && add background && showSearch

* showCancel 更名为 showAction && 增加 slot action

* add search test code

packages/vant-css/src/search.css

@@ -1,26 +1,19 @@
 @import './common/var.css';
 
 .van-search {
-  position: relative;
+  display: flex;
+  align-items: center;
   box-sizing: border-box;
   padding: 4px 15px;
-  background-color: #F2F2F2;
 
-  &--focus {
-    padding-right: 50px;
-  }
-
-  &--showcase {
-    padding: 10px;
-    background-color: $background-color;
-
-    .van-search__input-wrap {
-      border-color: $gray-light;
-    }
+  &--show-action {
+    padding-right: 0;
   }
 
   &__input-wrap {
     position: relative;
+    flex: 1;
+    height: 16px;
     padding: 8px 24px 8px 35px;
     border: 1px solid $gray-light;
     border-radius: 4px;
@@ -49,13 +42,14 @@
     }
   }
 
-  &__cancel {
-    position: absolute;
+  &__action {
     line-height: 34px;
-    padding: 4px 0;
-    top: 0;
-    right: 10px;
     font-size: 14px;
+    letter-spacing: 1px;
+  }
+
+  &__action-text {
+    padding: 0 10px;
     color: $green;
   }
 
@@ -73,9 +67,11 @@
     font-size: 14px;
     line-height: 16px;
     position: absolute;
-    right: 5px;
+    right: 0;
     top: 50%;
     transform: translateY(-50%);
+    /* 增加 clear 点击区域 */
+    padding: 5px;
     color: #888;
   }
 }