Add objectFit: "auto-cover"

[vassbence]

Some people already started discussing this at #186

The idea would be to create a new objectFit value which would automatically find the best fit based on the images width/height.

This can be done in user land like so:

... calculated the width and height of the image ...

<Cropper
  ...
  objectFit={width > height ? 'vertical-cover' : 'horizontal-cover'}
/>

but it would be nice if the package itself contined it as it is a fairly common use case.

[github-actions]

🚀 Issue was released in v4.2.0 🚀