Port to @vue/composition-api instead of vue-class-component

[maartenvn]

The new composition API for Vue 3 is available under the official @vue/composition-api package. Since the composition API will be natively supported in Vue 3, it may be in our best interest to start using that instead. It will allow for:

• Better Typescript support
• Native implementation over a 3th party library
• Easier migration to Vue 3 down the line
• Easier to learn due to more resources available (part of the Vue core)

[maartenvn]

@mcbloch Thoughts?

[mcbloch]

I'm all for keeping up to date with the library and having better typescript support.

This looks like a lot of work though, when do you see this happening?

[maartenvn]

After the exams and I could start tonight on the Pannenkoeken codenight!