Narrow Vue component type

The return type of the `vueComponentProp()` function is `object | string`. It has to be so broad to allow Vue 2 and Vue 3 component options or instances. If you are able to narrow the type without pulling in heavy dependencies, please comment here or submit a pull request!

See https://github.com/FloEdelmann/vue-ts-types/blob/main/README.md#vuecomponentpropvalidator-validator.