Processing check-filter event in root instace

In the last few videos, we've sent filter state up the DOM tree and received it in the root-level Vue instance.

Our objective, though, is to receive the data in the movie-list component so it can be used to filter the list of movies shown to the user.

In this video, we're going to consolidate the filter state into a single object in the root instance so we're ready to pass it via props to movie-list.