add CardEditor and modal to deck creation workflow and lift DeckEditor state

[kdduan]

48 #33

Overview

• Added model that prompts the user to create an account or login, or to continue as a guest.
• Lifted DeckEditor state - DeckEditor will be largely presentational now
• Added onModalClose callback function so that the deck's data is saved when the user opts to continue as guest

Testing

create a deck page:

finalize deck details modal:

To Do:

• mock the API call needed when closing the modal
• refactor the modal so that it includes the LogIn and SignUp components instead of navigating to the page
• add the onSave callback to the CardEditor component