Display help message when testnet launches successfully

[nbacquey]

Here is an example of the help message generated when cardano-testnet successfully starts:

    [...]
    forAll72 =
      Workspace: /tmp/nix-shell.yBvIzE/nix-shell.n6EEOb/testnet-test-e17490eb95ba9e3a
  
    This failure can be reproduced by running:
    > recheckAt (Seed 3328579059507353818 11797048402419991361) "1:" <property>
  
Please disregard the message above implying a failure.

Testnet is running with config file /tmp/nix-shell.yBvIzE/nix-shell.n6EEOb/testnet-test-e17490eb95ba9e3a/configuration.yaml
Logs of the SPO node can be found at /tmp/nix-shell.yBvIzE/nix-shell.n6EEOb/testnet-test-e17490eb95ba9e3a/logs/node1/stdout.log

To interact with the testnet using cardano-cli, you might want to set:

  export CARDANO_NODE_SOCKET_PATH=/tmp/nix-shell.yBvIzE/nix-shell.n6EEOb/testnet-test-e17490eb95ba9e3a/socket/node1/sock
  export CARDANO_NODE_NETWORK_ID=42

Type CTRL-C to exit.

Closes #6270

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• CI passes. See note on CI. The following CI checks are required:
  • Code is linted with hlint. See .github/workflows/check-hlint.yml to get the hlint version
  • Code is formatted with stylish-haskell. See .github/workflows/stylish-haskell.yml to get the stylish-haskell version
  • Code builds on Linux, MacOS and Windows for ghc-9.6 and ghc-9.12
• Self-reviewed the diff

Note on CI

If your PR is from a fork, the necessary CI jobs won't trigger automatically for security reasons.
You will need to get someone with write privileges. Please contact IOG node developers to do this
for you.

[Jimbo4350]

This is why we shouldn't be using properties. They only ought to be used in property testing.

[carbolymer]

I think you mean PropertyT IO as a base monad for testnet setup?

I think I saw someone complaining about cardano-testnet exeuctable console output breaking some tooling because it was detecting colours incorrectly.