2D 材质缺少与 Unlit 类似的 tilingOffset 功能

[cptbtptpbcptdtptp]

Describe the bug
开发 2D 项目时，想实现无限背景滚动，如果用 Unlit 材质 + Mesh，需要适配 3D 与 2D 的单位，如果用 SpriteRenderer ，没有类似 tilingOffset 的功能

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.

[GuoLei1990]

如果支持对于和 Sprite.rect 上使用区别优劣和价值如何考虑的