[FEAT] Add Dutch translations to App package

[SomeMoosery]

⚠️ IMPORTANT: Please fill out this template to give us as much information as possible to consider/implement the feature.

Prerequisites

• check this box if you have completed the following:
  • Reviewed the contributing guidelines and support files
  • Reviewed the README file for the repository you are working in
  • Searched for relevant instructions on our Discord server
  • Searched the issues of the repository you are working in to make sure one was not already filed

Summary

• Integrate Dutch translation .json file into the App package
• Replace all relevant instances of hardcoded text with text using the useTranslation hook

Motivation

To integrate Dutch (and other languages) into Blockstack's auth flow