TDNavBarItem: 新增 customWidget 参数替代已废弃的 iconWidget (#881)

* fix: 删除

* fix: 增加customWidget

* fix: 修改对应文档

---------

Co-authored-by: yiqiuzheng <yiqiuzheng@tencent.com>

Author: zyqq

tdesign-component/example/assets/api/navbar_api.md

@@ -38,8 +38,9 @@
 | 参数 | 类型 | 默认值 | 说明 |
 | --- | --- | --- | --- |
 | action | TDBarItemAction? | - | 操作回调 |
+| customWidget | Widget? | - | 自定义组件，优先级高于 icon，可以是任意 Widget |
 | icon | IconData? | - | 图标 |
 | iconColor | Color? | - | 图标颜色 |
 | iconSize | double? | 24.0 | 图标尺寸 |
-| iconWidget | Widget? | - | 图标组件，优先级高于 icon |
+| ~~iconWidget~~ | Widget? | - | 已废弃，请使用 customWidget 代替 |
 | padding | EdgeInsetsGeometry? | - |  |

tdesign-component/example/assets/code/swipecell._buildSwiper3Cell.txt

@@ -281,7 +281,11 @@ class TDNavBarItem {
   /// 内部填充
   EdgeInsetsGeometry? padding;
 
+  /// 自定义组件，优先级高于 icon，可以是任意 Widget
+  Widget? customWidget;
+
   /// 图标组件，优先级高于 icon
+  @Deprecated('Use customWidget instead')
   Widget? iconWidget;
 
   TDNavBarItem({
@@ -290,6 +294,8 @@ class TDNavBarItem {
     this.action,
     this.iconSize = 24.0,
     this.padding,
+    this.customWidget,
+    @Deprecated('Use customWidget instead')
     this.iconWidget,
   });
 
@@ -302,7 +308,7 @@ class TDNavBarItem {
               (isLeft
                   ? EdgeInsets.only(right: TDTheme.of(context).spacer8)
                   : EdgeInsets.only(left: TDTheme.of(context).spacer8)),
-          child: iconWidget ??
+          child: customWidget ?? iconWidget ??
               Icon(
                 icon,
                 size: iconSize,

tdesign-component/example/assets/code/swipecell._buildSwiperCell.txt

@@ -328,10 +328,11 @@ import 'package:tdesign_flutter/tdesign_flutter.dart';
 | 参数 | 类型 | 默认值 | 说明 |
 | --- | --- | --- | --- |
 | action | TDBarItemAction? | - | 操作回调 |
+| customWidget | Widget? | - | 自定义组件，优先级高于 icon，可以是任意 Widget |
 | icon | IconData? | - | 图标 |
 | iconColor | Color? | - | 图标颜色 |
 | iconSize | double? | 24.0 | 图标尺寸 |
-| iconWidget | Widget? | - | 图标组件，优先级高于 icon |
+| ~~iconWidget~~ | Widget? | - | 已废弃，请使用 customWidget 代替 |
 | padding | EdgeInsetsGeometry? | - |  |