cardano-testnet: show in types the two scenarios that are supported

[smelc]

Warning

This PR does not compile, this is intended. This is for demonstration only.

This PR is meant to show possible follow-ups of #6148, i.e. how we would implement these remarks of mine:

Have pTestnetNodeOptions return a list of TestnetNodeOption and TestnetNodeOption be UserProvidedNodeOptions Filepath | SpoNodeOptions [Srting] | RelayNodeOptions [ String]. In other words merge the types TestnetNodeOptions and AutomaticNodeOption. This will generalize the behavior so that the user can create multiple nodes, no matter whether they are using custom options or using default behavior (Spo or Relay). This will require a bit of generalization in Cardano.hs but not much.

This is shown in the first commit of this PR.

Reflect in the types the tying behavior between the node configuration file being passed by the user and the genesis files being passed by the user too.

This is shown in commits 2 and 3 of this PR

[github-actions]

This PR is stale because it has been open 45 days with no activity.