updates sign command to use ui.ledger for ledger signing

[hughy]

Summary

the 'ledger' function from the ui module handles a variety of errors from the ledger app. using the ui function to wrap the app interactions improves user experience over calling the ledger sign method directly

Closes IFL-3149

Testing Plan

1. create an unsigned transaction from a ledger account using wallet:send --unsignedTransaction
2. checkout the staging branch
3. without connecting your ledger, use wallet:transactions:sign to attempt to sign the transaction and observer that the command crashes with an error

4. checkout this branch
5. repeat step 3 but observe that the command catches the error and instructs you to connect and unlock your ledger

Documentation

Does this change require any updates to the Iron Fish Docs (ex. the RPC API
Reference)? If yes, link a
related documentation pull request for the website.

[ ] Yes

Breaking Change

Is this a breaking change? If yes, add notes below on why this is breaking and label it with breaking-change-rpc or breaking-change-sdk.

[ ] Yes