* One use statement
* Add stdin uri scheme
* Convert parse_signer_source to return Result
* A-Z deps
* Convert Usb data to Locator
* Pull DerivationPath out of Locator
* Wrap SignerSource to share derivation_path
* Review comments
* Check Filepath existence, readability in parse_signer_source
* Rename (keypair util is not a thing)
* Add method to generate_unique_signers
* Cli: refactor signer handling and remote-wallet init
* Fixup unit tests
* Fixup intergation tests
* Update keypair path print statement
* Remove &None
* Use deterministic key in test
* Retain storage-account as index
* Make signer index-handling less brittle
* Cache pubkey on RemoteKeypair::new
* Make signer_of consistent + return pubkey
* Remove &matches double references
* Nonce authorities need special handling
* Add fallible methods to KeypairUtil
* Add RemoteKeypair struct and impl KeypairUtil
* Implement RemoteKeypair in keygen; also add parse_keypair_path for cleanup