Switch from Endpoint Factory to pure FastAPI application

[vincentsarago]

If we want to follow the Core specification (Part 1) we need to conform the landing page (/) and it HAS TO have the service-doc or service-desc links. Those links are defined at the FastAPI application level and not at the router level (which we create with the endpoint factory).

IMO for this project it will be ok to move away from the endpoint factory to a app factory (e.g stac-fastapi)

[vincentsarago]

After talking with @bitner, the application factory is not a model we need/want because we want to keep the possibility to import routes to pre-built application.

The main problem of the EndpointFactory we have right now is how the landing page links are created (we need to have access to the service-doc and service-desc path that are defined at FastAPI application level and not at Router level.