Keep state centralized in a store

[luizribeiro]

Right now we can't check the print status from anywhere other than the PrintStatus component.

This means we can't block Print buttons from being clicked when there is an in-progress print, for example.

Another advantage is that switching between tabs on the app wouldn't trigger a loading spinner every time.

Redux would likely be overkill here, so maybe something like react-easy-state would be sufficient to keep this global state.