Add UI for Loading and Empty DataStates for Android and iOS

[brady-aiello]

DataState is defined with 4 subclasses:

• Error
• Loading
• Success
• Empty

But we are only changing the UI for 2 states: Success and Error in iOS and Android

Loading should show a Swipe-refresh style spinner Empty (different issue) should just a TextView saying that there weren't any breeds, and perhaps to try again later.

[kpgalligan]

Just a note for tomorrow morning. To discuss if we want to implement this.

[JuliaJakubcova]

This task has been done already.