fix(module:tabs): fix dropdown style (#5659)

components/tabs/style/patch.less

@@ -1,5 +1,54 @@
+@import './index';
+
 nz-tabset,
 nz-tab-nav-operation,
 nz-tabs-nav {
   display: block;
 }
+
+
+.nz-tabs-dropdown.ant-dropdown {
+
+    .ant-dropdown-menu {
+      max-height: 200px;
+      margin: 0;
+      padding: @dropdown-edge-child-vertical-padding 0;
+      overflow-x: hidden;
+      overflow-y: auto;
+      text-align: left;
+      list-style-type: none;
+      background-color: @dropdown-menu-bg;
+      background-clip: padding-box;
+      border-radius: @border-radius-base;
+      outline: none;
+      box-shadow: @box-shadow-base;
+
+      &-item {
+        min-width: 120px;
+        margin: 0;
+        padding: @dropdown-vertical-padding @control-padding-horizontal;
+        overflow: hidden;
+        color: @text-color;
+        font-weight: normal;
+        font-size: @dropdown-font-size;
+        line-height: @dropdown-line-height;
+        white-space: nowrap;
+        text-overflow: ellipsis;
+        cursor: pointer;
+        transition: all 0.3s;
+
+        &:hover {
+          background: @item-hover-bg;
+        }
+
+        &-disabled {
+          &,
+          &:hover {
+            color: @disabled-color;
+            background: transparent;
+            cursor: not-allowed;
+          }
+        }
+      }
+    }
+}

components/tabs/tab-nav-operation.component.ts

@@ -33,7 +33,7 @@ import { NzTabNavItemDirective } from './tab-nav-item.directive';
       type="button"
       tabindex="-1"
       aria-hidden="true"
-      nzOverlayClassName="ant-tabs-dropdown-menu"
+      nzOverlayClassName="nz-tabs-dropdown"
       #dropdownTrigger="nzDropdown"
       [nzDropdownMenu]="menu"
       [nzOverlayStyle]="{ minWidth: '46px' }"