Add async worker capabilities

[gitbuda]

TODOs

• [x] Make the async call proof of concept
• [x] Implement Async::Connection::Execute returning all records
• [x] Implement all functionalities exposed in the C++ wrapper for mgclient
• [x] Leave only async stuff in index.js
• [x] Refactor error handling
• [x] Consolidate state management (just ensure C++ client is used properly, parallel executions, etc).
• [x] Update tests to use the async capabilities
• [x] Add TypeScript stuff

Based on

• https://github.com/nodejs/node-addon-api
• https://github.com/apache/pulsar-client-node