Implement the Facility interface and microservice

[aeshub]

Describe the new feature you would like to see A FacilityController combined with a FacilityService should replace existing functionality talking to Echo and other relevant third-party applications. The goal is to have a solution in Flotilla which can talk to an external microservice through configuration instead of being tie to Echo. This will enable others to use Flotilla more easily without having a specific requirement for Echo.

Describe the solution you'd like The existing EchoController should be replace by a FacilityController which handles requests from the frontend which are redirected to Echo. It will then use a FacilityService which makes calls to an external microservice through an HTTP request. The host and port of the microservice should be configurable.

The microservice should be hosted as a docker container with a default dummy implementation available in the Flotilla repository. For Equinor a different repo should be made to create the Echo facing microservice. The system as a whole should be designed such that a different operator could create their own microservice and use that with the system instead of the dummy or Echo.

Suggested solution is to use botnet for the microservice.

How will this feature affect the current Threat Model? This will introduce new HTTP requests which require authentication on the microservice side.

[aeshub]

This will replace #1580

[andchiind]

👀👀 https://camunda.com/blog/2022/09/seven-best-programming-languages-for-microservices/#haskelllanguage