Helpers for the Ledger Bitcoin application [WIP]

A transport implementing the ledger_hw trait is needed in most of the helpers.

example:

```rust use bitcoin::util::bip32; use ledgerhwappbtc::getwalletpublickey; use ledgerhwappbtc::AddressFormat; use ledgerhwtransporthid::HidTransport; use std::str::FromStr;

[tokio::main]

async fn main() { let transport = HidTransport::new().unwrap(); let path = bip32::DerivationPath::fromstr("m/44'/0'/0'/0/0").unwrap(); let (pk, address, chaincode) = getwalletpublickey(&transport, &path, true, AddressFormat::Legacy) .await .unwrap(); println!("pk: {}", pk); println!("address: {}", address); println!("chaincode: {}", chaincode); } ```

TODO:

mod wallet

• [x] getwalletpublic_key
• [x] gettrustedinput
• [x] sign_message
  • [ ] signmessageprepare
    • [ ] signmessagepreparev1
    • [ ] signmessagepreparev2
  • [x] signmessagesign
• [x] startuntrustedhashtransactioninput [need test]
• [ ] finalize_input [need test]
• [x] untrustedhashsign [need test]

mod util

• [x] getfirmwareversion