Upgraded @babel/preset-env and core-js

[costaraphael]

This PR upgrades core-js and @babel/preset-env to their latest stable versions.

This will bring some improvements in bundle size (more details here) and reduce some incompatibility issues with Storybook (there could be more tools, but I've only experienced issues with Storybook).

[costaraphael]

Assuming this PR will go through, and although the build is running fine, is there a way to release this as a beta, or RC first?

Given the nature of the change, I'd feel safer if I took it for a spin on my project just to confirm everything still works fine. :slightly_smiling_face:

[harmon25]

Will probably be incorporating this in an upcoming project - so I would also be willing to try it out!

Was going to suggest a branch with the dist/ included - but because this is a monorepo - may not be easy to include as an npm dep...

[Adzz]

Is there a workaround to be able to include this as this library seems abandoned...