fix: avoid breakage by not to auto augment hooks type

[ktsn]

#371 was technically a breaking change because the users cannot declare the same name property with hooks as we restrict property types.

For example, there are users declaring data property as just a data:

@Component
class MyComp extends Vue {
  data = 'my data'
}

Since v7.2.0, above code produces compile error as it conflicts data hook type. https://github.com/vuejs/vue-class-component/blob/master/src/lifecycle.ts#L5

Although IMO it should be avoided to use the same name with hooks for property name to avoid confusion, this had been working in the previous version. So we should keep that behavior.

To solve this problem, I disabled the type augmentation by default. When users want to use it, they can manually import it via vue-class-component/hooks.

// main.ts
import 'vue-class-component/hooks'
import Vue from 'vue'
import App from './App.vue'

new Vue({
  render: h => h(App)
}).$mount('#app')