[refactoring] refactor all error messages, form text into a json file

[roshaans]

Similarly to Near-wallet , it would be helpful to refactor the app so that all form text, error messages, and descriptive text are documented and sourced from a single json file.

This will help us to keep a common language in the app and keep us from worrying about having to change a given text in all parts of the application as well as help us roll out translations further down the road.

brought up by @Patrick1904 in #147 (comment)_

[Patrick1904]

Yes we might as well add necessary framework to support multiple languages should it be needed in the future. The NEAR Wallet currently uses react-localize-redux, however, the package is barely maintained anymore and I suggest we research a better option.