TSM-06: convert Group A services to TypeScript

[Justin Hammond (Justintime50)]

Summary

Converts Group A service modules to TypeScript and applies minimal typed compatibility fixes needed for the current base-service conversion, with runtime behavior preserved.

Changes in this PR

• renames Group A service files to .ts:
  • src/services/address_service.ts
  • src/services/parcel_service.ts
  • src/services/customs_info_service.ts
  • src/services/customs_item_service.ts
  • src/services/shipment_service.ts
• adds minimal type-safe wrapper map annotations where property writes are dynamic
• updates conversion helper callsites to pass params consistently with current base service signatures
• introduces no new ts-nocheck

Testing

• npm run typescript
• npm run build
• npx eslint src/services/address_service.ts src/services/parcel_service.ts src/services/customs_info_service.ts src/services/customs_item_service.ts src/services/shipment_service.ts
• npx vitest run test/services/address.test.js test/services/parcel.test.js test/services/customs_info.test.js test/services/customs_item.test.js test/services/shipment.test.js test/services/module_exports_compat.test.js

Notes

• targeted service suites above are blocked locally without EASYPOST_TEST_API_KEY; module export compatibility test is included in the command set.