[Feature] Add a subpath to the server URL

[GoComputing]

This server might be deployed in a homelab, where several services shares the same URL. A typical method of routing these services are the URL paths. Lets say we have three services (serviceA, serviceB and serviceC). We also have one unique URL for these services (my-url.com). Then, the routing might be configured so that my-url.com/serviceA redirects to the service A, and so on. If service A had an original URL path of my-url.com/path/to/resource, then it would become my-url.com/serviceA/path/to/resource. This must be configured on both the routing proxy server and the application itself.

I suggest adding this feature to this server. It would require modifying the routes source files (AuthRoutes.kt, FavouriteRoutes.kt, ...) so that they respond to the subpath. This subpath might be configured in the application.conf so that it is read from the environment variable (and so it is easily configurable in the .env file for docker/docker-compose containers).