Release Notes:

• N/A

Fix this long-standing issue so that we can support Link hover colors.

And renamed text_layout example to text_style.

I spent some time studying the process of this text style change and found it a bit complicated.

At first, I thought there was a problem with refine and it was not passed properly. After changing it, I found that it was not the problem.

Then I found that it was because TextRun had already stored the color, background, underline, strikethrough in TextRun in the request_layout stage. They area calculate at the request_layout stage, but request_layout stage there was no hitbox, so the hover state was not obtained.

cargo run -p gpui --example text_style