Create API to communicate with Auth Project

[misha130]

Is your feature request related to a problem? Please describe.
In the auth project upon registration a member has to be created. Thus it needs to signal to the core project to make such a member and return a result if successful so registration can be done.

Describe the solution you'd like
An API project that does the following:

• Makes an authentication with the auth project or vice versa
• A concise API structure that can be easily used (maybe gRPC, see https://github.com/misha130/core/tree/api for an example)

Describe alternatives you've considered
Other than gRPC its easy to create a good old REST API. Problem is with so many microservices for instance a service for imports it might be better to use gRPC.