chore(shims): make vue shim use defineComponent

 Allows .vue single file components to be imported and used. Since
 the Global Vue API has been deprecated, this file needs to import
 the return type of defineComponent for TypeScript to be able to
 import and use the single file components.

src/shims-vue.d.ts

@@ -1,4 +1,5 @@
 declare module '*.vue' {
-  import Vue from 'vue';
-  export default Vue;
-}
+  import { defineComponent } from 'vue';
+  const component: ReturnType<typeof defineComponent>;
+  export default component;
+}