refactor: add formatter, linter, CI checks and update all dependencies

[marcalexiei]

To celebrate the "Seekers of the Storm" expansion upcoming release 🎉 I made some improvements to the app:

• all dependencies and dev dependencies have been updated
• added prettier
• added eslint
• added new CI workflow which controls that build, format and lint tasks are executed successfully on:
  • push on main branch
  • pull_request
• firebase-hosting-merge workflow has been changed to be executed
  • automatically after a successful run of CI workflow on main branch.
  • manually from the GitHub Actions page

[!NOTE] I created multiple commits to highlight each change and, hopefully, simplify the review process without the need to open many PRs. Furthermore I'm going to add a review comment on each relevant source change. Anyway I understand if this is too much 😅 so let me know if your prefer separate PRs