Osmscout-server includes a setting in its UI to create a systemd user
service and socket to run the server on demand. This does not function
correctly on NixOS, for two reasons:
1. It assumes that the binary path is stable (e.g.
/usr/bin/osmscout-server), which is not the case on NixOS.
2. It auto-detects the unwrapped binary path, which doesn't work.
This module allows the user to access the same functionality on NixOS.
