Mod reco

Changed reconstruction stage to a similar scheme as the new oscillation stage (base service with several derived services). This should allow for easier adding of alternative reco methods. E.g. parametrized reco, which is to follow soon.
If you want it as an option only for the developers, than you should omit it here, and only leave it in `construct_KDEs`. Otherwise it can be overwritten by the `settings.json`