Refactor SignerSource to expose DerivationPath to other kinds of signers (#16933)

* 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

clap-utils/src/input_parsers.rs

@@ -1,19 +1,21 @@
-use crate::keypair::{
-    keypair_from_seed_phrase, pubkey_from_path, resolve_signer_from_path, signer_from_path,
-    ASK_KEYWORD, SKIP_SEED_PHRASE_VALIDATION_ARG,
+use {
+    crate::keypair::{
+        keypair_from_seed_phrase, pubkey_from_path, resolve_signer_from_path, signer_from_path,
+        ASK_KEYWORD, SKIP_SEED_PHRASE_VALIDATION_ARG,
+    },
+    chrono::DateTime,
+    clap::ArgMatches,
+    solana_remote_wallet::remote_wallet::RemoteWalletManager,
+    solana_sdk::{
+        clock::UnixTimestamp,
+        commitment_config::CommitmentConfig,
+        genesis_config::ClusterType,
+        native_token::sol_to_lamports,
+        pubkey::Pubkey,
+        signature::{read_keypair_file, Keypair, Signature, Signer},
+    },
+    std::{str::FromStr, sync::Arc},
 };
-use chrono::DateTime;
-use clap::ArgMatches;
-use solana_remote_wallet::remote_wallet::RemoteWalletManager;
-use solana_sdk::{
-    clock::UnixTimestamp,
-    commitment_config::CommitmentConfig,
-    genesis_config::ClusterType,
-    native_token::sol_to_lamports,
-    pubkey::Pubkey,
-    signature::{read_keypair_file, Keypair, Signature, Signer},
-};
-use std::{str::FromStr, sync::Arc};
 
 // Return parsed values from matches at `name`
 pub fn values_of<T>(matches: &ArgMatches<'_>, name: &str) -> Option<Vec<T>>