Terra-core: [terra-toggle] Update animation to ease-out

[yuderekyu]

Feature Request

Petition to update the animation on terra-toggle from linear to ease-out.

Easing out is typically the best for user interface work, because the fast start gives your animations a feeling of responsiveness, while still allowing for a natural slowdown at the end.

https://developers.google.com/web/fundamentals/design-and-ux/animations/the-basics-of-easing?hl=en

[neilpfeiffer]

Fine by UX, no blocks, anyone is free to add this enhancement and submit a PR.

[manjusr]

I intend to work on this enhancement, update terra-toggle animation to ease-out and submit a PR once done.