Add support for M3 Badges

The [Material 3 spec](https://m3.material.io/) has been updated to include [badges](https://m3.material.io/components/badges/overview):

<img width="330" alt="Screen Shot 2022-10-25 at 12 47 59 PM" src="https://user-images.githubusercontent.com/19588/197868585-e9352ca5-1855-4686-a0f8-7449be74ea3b.png">

We should add support for these to the Flutter Material library.
