Chore(RPC): Improve Error Messaging for Invalid Descriptors in loaddescriptor RPC

[moisesPompilio]

Description and Notes

Error messaging for the loaddescriptor RPC has been improved to provide more detailed feedback when a descriptor is invalid. Previously, the RPC only returned a generic "invalid descriptor" error, which was insufficient for diagnosing the actual issue. Descriptors can be invalid for many reasons: incorrect checksums, using private keys instead of public keys (which are not accepted by the project), malformed syntax, and more.

Now, the specific parsing error is returned to the user, making it easier to identify and fix the problem. Additionally, documentation for the loaddescriptor RPC has been added, including parameter descriptions and usage notes accessible via the CLI.

How to verify the changes you have done?

• Test with descriptors that use private keys instead of public keys:

  floresta-cli -n regtest loaddescriptor "wpkh(tprv8hCwaWbnCTeqSXMmEgtYqC3tjCHQTKphfXBG5MfWgcA6pif3fAUqCuqwphSyXmVFhd8b5ep5krkRxF6YkuQfxSAhHMTGeRA8rKPzQd9BMre/0/*)#amzqvgzd"
  

• Test with descriptor that use invalid public key

  floresta-cli -n regtest loaddescriptor "wpkh(tpubDDtyive2LqLWKzPZ8LZ9Ebi1JDoLcf1cEpn3Mshp6sxVfCupHZJRPQTozp2EpTF76vJcyQBN7VP7CjUntEJxeADnuTMNTYKoSWNae8soVyy/1/*)#6ljl9tyc"
  

• Test with descriptors that have incorrect checksums:

  floresta-cli -n regtest loaddescriptor "wpkh(tpubDDtyive2LqLWKzPZ8LZ9Ebi1JDoLcf1cEpn3Mshp6sxVfCupHZJRPQTozp2EpTF76vJcyQBN7VP7CjUntEJxeADnuTMNTYKoSWNae8soVyv/1/*)#0rlhs7rd"
  

• Verify that detailed, actionable error messages are returned in each case, clearly indicating what went wrong during descriptor parsing.
• Check the CLI documentation for loaddescriptor to ensure parameter descriptions and usage notes are present and accurate.

  floresta-cli -n regtest loaddescriptor --help
  

[jaoleal]

Conpept ACK.

Thanks for doing this, just some comments.

[jaoleal]

LGTM, can you just ammend and push to retrigger the CI ?

[moisesPompilio]

I added descriptor persistence at the end of the load_descriptor function, so before returning true in the RPC, it saves the descriptor.

[jaoleal]

ACK 3b277a9

[jaoleal]

ACK 6ed98e8

[Davidson-Souza]

ACK 6ed98e8