Use CSS Animations for entry and exit animations

[joaom00]

This PR adds the use of CSS animations for Vaul entry and exit animations, making the code for managing the open state simpler.

I also refactored the logic of the scaleBackground function by changing

• Taking advantage of the Content component to be mounted/unmounted when the dialog is open or closed
• Created two utility functions assignStyle and chain that together facilitate the editing of styles and their cleaning

Fixes #292

[vercel]

@joaom00 is attempting to deploy a commit to the emil Team on Vercel.

A member of the Team first needs to authorize it.

[rortan134]

Also closes #351