chore: update form demo

[Summer-Shen]

🤔 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

• 📌 [示例代码改造] 使用Space组件替换示例代码 #1281

💡 需求背景和解决方案

用 space 组件替换更新 form 的示例代码

📝 更新日志

• chore: 用 space 组件替换更新 form 的示例代码

• 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。⚠️

• 文档已补充或无须补充
• 代码演示已提供或无须提供
• TypeScript 定义已补充或无须补充
• Changelog 已提供或无须提供

[codecov-commenter]

Codecov Report

Merging #1368 (648bdd5) into develop (492d477) will increase coverage by 0.22%.
The diff coverage is 67.35%.

@@             Coverage Diff             @@
##           develop    #1368      +/-   ##
===========================================
+ Coverage    57.94%   58.16%   +0.22%     
===========================================
  Files          407      412       +5     
  Lines        15371    15441      +70     
  Branches      2931     2929       -2     
===========================================
+ Hits          8907     8982      +75     
- Misses        6187     6189       +2     
+ Partials       277      270       -7     

Impacted Files	Coverage Δ
src/button/props.ts	84.61% <0.00%> (-15.39%)	⬇️
src/calendar/const.ts	100.00% <ø> (ø)
src/cascader/cascader.tsx	64.00% <ø> (ø)
src/color-picker/color-picker.tsx	81.25% <ø> (ø)
src/color-picker/panel/header.tsx	69.56% <ø> (-1.27%)	⬇️
src/date-picker/base/Header.tsx	7.57% <0.00%> (-0.37%)	⬇️
src/date-picker/date-picker-panel-props.ts	100.00% <ø> (+90.00%)	⬆️
src/date-picker/date-range-picker-panel-props.ts	100.00% <ø> (+90.90%)	⬆️
src/date-picker/date-range-picker-props.ts	42.85% <0.00%> (-11.69%)	⬇️
src/date-picker/hooks/useRange.ts	35.89% <ø> (ø)
... and 173 more

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[github-actions]

[uyarn]

@Summer-Shen 方便的话 这个demo也优化下 登录按钮应该和输入框等宽

[Summer-Shen]

@uyarn 登陆表单 demo 已经改好了，感谢！