Implement Provide, Inject, and Reactive from the new Vue3 API

[JustSteveKing]

Provide, Inject and Reactive on the new Vue3 API seems to be a good alternative to reactive data in a Vue component. I am however only just getting caught up with the documentation - so this could change as the release date comes closer and a solid release candidate is announced.

[PatrikBird]

ref and reactive replace the data property from the options API. The big benefit is that reactive state can be shared in an easy way across various components. There's no other way than implementing them when using the Composition API.