refactor(backend): move dir to packages/backend

[RickyC0626]

What change does this PR introduce?

• Moved backend/ to packages/backend
• Pre-commit hook for backend has been updated to work with the new path
• CI workflows have been updated with the new path

Why was this change needed?

This will help set up the foundation for lerna changes that will require backend to be in packages/

• chore(setup): lerna for monorepo package versioning #56

Other information (screenshots)

Checklist

• 📝 I have reviewed my code prior to submission
• ❔ Issue number has been linked (if applicable)
• 🧪 Tests have been added or updated (if applicable)
• 📖 Documentation has been updated (if applicable)
• 📸 Screenshots added (if applicable)