Working on persistence: import the JSON converter from the dart:convert library.
Added a named constructor to the PirateName class, that creates new PirateName instance from a JSON-encoded string.
Added a getter to the PirateName class that encodes a pirate name in a JSON string.
Declaring a top level string that will serve as the key for the value that is pirate name.
Save the pirate name when the badge name changes.