Tidy up & finalise data structures

[dmythro]

Checklist

• Re-build additional data
• Change remaining comma-separated strings to arrays
• Check/consider issues & PRs
  • Continents enum #105
  • Enable tree shaking with countries-list #106
  • Turkey changed to AS and EU from AS #45
  • Data update: Swaziland has been renamed to Eswatini #72
  • Data update: Croatia currency change from HRK to EUR #107
  • Data update: native field for Nepal #114
  • Error in SQL table structure #115
  • Some countries contain diacritic characters #103, add tests
  • Helper functions #96, add tests
• Review and fix minor issues
• Order tasks for CI pipeline

References

• ECMAScript Modules in Node.js, also this, this and this.
• Turborepo