refactor: core API

[AVVS]

Goal of this task is to ensure that core modular API of microservice module is similar to standard one of hapi, koa, express, seneca, etc

We want to take the best familiar method names & use that instead of home-brewed methods that were designed at a time. Functionality should remain the same, but better naming is required.

Furthermore, we need to add more checks to simplify development for others not that familiar with the toolkit