feat(Upload): requestData support array

[GATING]

🤔 这个 PR 的性质是？

• 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

[Upload] 文件数组上传不支持#4188

💡 需求背景和解决方案

修改前：

当多个文件一个请求上传，file这个参数被转成了字符串[object File],[object File]，这个是无意义的。
且后端也可能会接收数组形式的参数。

修改后：

📝 更新日志

• feat(Upload): 请求参数支持数组

• 本条 PR 不需要纳入 Changelog

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[Copilot]

PR Overview

This PR adds support for sending array parameters in the Upload request by modifying the FormData construction logic.

• Introduces a check for array values in requestData to append each element individually
• Maintains backward compatibility by appending non-array values as before

Reviewed Changes

File	Description
js/upload/xhr.ts	Enhances FormData handling to support array values in requestData

Copilot reviewed 1 out of 1 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

js/upload/xhr.ts:84

• [nitpick] Appending array elements using the same key may not be properly recognized by all backends. Consider appending array fields with a modified key (e.g. 'key[]') or verifying that the backend correctly handles multiple entries for the same key.

if (Array.isArray(dataValue)) {