feat: implement Sheets

- Implement the new component according to specs: https://m3.material.io/components/bottom-sheets/overview (Standard and Modal variants)
- Reuse newly introduced tokens (shape, motion, typography, color etc)
- Extract component specific tokens for easier maintenance.
- Get inspired from TextInput/TextField, Switch, Checkbox, FAB components which have gone through modernization.
- Showcase the component in the example app
- Update the documentation

从 Material Design 的 bottom-sheets 规范开始，并检查 TextInput/TextField、Switch、Checkbox 和 FAB 的现代化模式。然后检查示例应用和现有文档的入口点。当 Standard 和 Modal 变体使用可复用 token 和组件专用 token 实现、在示例应用中展示并完成文档编写时，即表示完成。

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