Add FavoritesView function to render favorites menu

- Takes band object as argument
- Band object passed to new instance of FavoritesPresenter.present
- FavoritesPresenter creates band content nodes which are appended to the new favorites menu container.
Add event listener for add_band button click

On click, favoritesView.draw will render new favorites menu and menu will appear on top of screen.

Add band variable in application_controller.js to store band object received from api call. Reuse object when appending to favorites menu object.