Path: Add support for configuring the transform from viewbox to Path

[tronical]

By default, we preserve the aspect ratio, but this isn't quite always what's wanted. So the fit-style property permits configuring this.

Fixes #8853

[ogoffart]

Shouldn't we reuse the ImageFit enum ?

https://docs.slint.dev/latest/docs/slint/reference/elements/image/#image-fit

[tronical]

I was contemplating, but it's called Image fit, the docs are quite image specific.

[ogoffart]

I think it would be worth merging it, don't you think? We could rename it (deprecate the old name)

I think also the "preserve" is interesting and could be used for many use case were you actually want the bounding box to be the same as the width/height of the item. Although I realize that this doesn't map 1:1

[tronical]

You're right. The task at hand is the same for both. I'll think about a better name for the enum and then make a PR to deprecate the old, introduce the new, and implement it for Path.