Release Notes:
- N/A
------
- Continue #24090 to fix text align for when used `whitespace_nowrap`.
- Fix wrapped line length calculation.
And add example
```
cargo run -p gpui --example text_layout
```
<img width="760" alt="image"
src="https://github.com/user-attachments/assets/a087c300-0e0e-4a80-98c6-90161a9b0905"
/>
---------
Co-authored-by: Owen Law <owenlaw222@gmail.com>
