fix cardano-node configuration

[brainrake]

• We use cardano-node configuration from cardano-configurations, which is not ideal because it requires version hunting per node version. Instead, use the configurations built in the cardano-node repo. See https://github.com/IntersectMBO/cardano-node/pull/699/files https://github.com/IntersectMBO/cardano-node/blob/c5d3d63b95b99c8000b5977948cb673dd89d28cc/flake.nix#L117
• provide a way to override settings
• share the settings between modules in a better way
• support multi-node configurations

[brainrake]

from Andrea:
I just found out that cardano-playground tags commits using the cardano-node versions. We can use that repository (always with flake = false) to fetch the configuration files.

[brainrake]

Fix is using configuration from services.cardano NixOS module from cardano-node, included in #102