Cardano Updates

### New features - Full Byron-Key Generation Support

This update brings full Byron-Era features to the `keygen` function. You can now:

- Generate the Root/Child Private- and Public-Keys for old 12 word Daedalus Byron mnemonics and a given Path like `0H/0H`

- Generate the Root/Child Private- and Public-Keys for old 15 word Yoroi Byron mnemonics and a given Path like `44H/1815H/0H/0/0`

- Generate the corresponding Byron-Addresses like ' DDz...'  and 'Ae2...'

- Write the generated Address to an Address-File
As the derivation path for Byron Daedalus wallets are totally random, this update also includes

- Auto derivation-path decryption from a given Daedalus-Address.

With this update, you can generate your private and public key of your old Byron/Yoroi Daedalus Wallet. If you have the mnemonics and the address itself, the correct derivation path will be calculated automatically.

All functions were coded also to have a reference code for other devs.

This update enabled users of older Byron-Wallets to manually sign the Midnight NIGHT Claim challenge.

- There is a new flag for the `signing` function in cardano-signer. You can specify `--signature-only` for the plaintext stdout so only the signature would be output. Normally also the public key is printed. This makes it even easier for 3rd party tools calling cardano-signer that just need the signature.

- You can now also use a file as content for the mnemonics for the `keygen` functions.

Breaking Changes:

- The `keygen` function to generate dRep-Keys is now generating the newer CIP129 dRep-ID by default. The json-extended output also contains the legacy CIP105 version too.