add：弹窗支持自定义宽度

[jflin19990707]

🤔 这个 PR 的性质是？

勾选规则:
1.只要有新增参数，就勾选”新特性提交“
2.只修改内部bug，未新增参数，才勾选”日常 bug 修复“
3.其他选项视具体改动判断

• 日常 bug 修复
• 新特性提交
• 文档改进
• 演示代码改进
• 组件样式/交互改进
• CI/CD 改进
• 重构
• 代码风格优化
• 测试用例
• 分支合并
• 其他

🔗 相关 Issue

#715
#732

💡 需求背景和解决方案

📝 更新日志

• fix(TDConfirmDialog): 弹窗支持自定义宽度，按钮增加自定义样式属性

• 本条 PR 不需要纳入 Changelog

☑️ 请求合并前的自查清单

⚠️ 请自检并全部勾选全部选项。⚠️

• pr目标分支为develop分支，请勿直接往main分支合并
• 标题格式为：组件类名: 修改描述（示例：TDBottomTabBar: 修复iconText模式，底部溢出2.5像素）
• ”相关issue“处带上修复的issue链接
• 相关文档已补充或无须补充

[tencent-adm]

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[Luozf12345]

flutter最新版本(3.32.8)编译成功

[Luozf12345]

设计走查流水线地址（xxx需换成内网域名）:https://devops.xxx.com/console/pipeline/tdesign-react/p-384cda2dd7654d75b3707c38b740901b/detail/b-299ef440a6e144ddb5b7bb1a00843620/outputs
体验apk: https://github.com/Luozf12345/tdesign_flutter_repo/blob/main/app-0.0.0.522-724-release.apk

[Luozf12345]

flutter最新版本(3.32.8)编译成功

[Luozf12345]

设计走查流水线地址（xxx需换成内网域名）:https://devops.xxx.com/console/pipeline/tdesign-react/p-384cda2dd7654d75b3707c38b740901b/detail/b-12d55a36b66e4278a7b462b5cc6ef749/outputs
体验apk: https://github.com/Luozf12345/tdesign_flutter_repo/blob/main/app-0.0.0.532-724-release.apk