Remove Jest

Replace jest by the node test runner

- [ ] dispatcher.spec.ts
- [ ] events.spec.ts
- [ ] externals.spec.ts
- [ ] handle-inactive-no-backup.spec.ts
- [ ] handle-inactive-with-backup.spec.ts
- [ ] incomer.spec.ts
- [ ] registration.spec.ts
- [ ] transaction-handler.spec.ts
- [ ] transaction.spec.ts

Feel free to re-arrange and improve test cases ;)