Refactor remote-wallet path parsing (backport #16798) (#16893)

* SDK: More conversions for `Pubkey`

(cherry picked from commit 9b7120bf73)

* SDK: More conversion for `DerivationPath`

(cherry picked from commit 722de942ca)

* remote-wallet: Add helpers for locating remote wallets

(cherry picked from commit 64fcb792c2)

# Conflicts:
#	Cargo.lock

* remote-wallet: Plumb `Locator` into `RemoteWalletInfo`

(cherry picked from commit 3d12be29ec)

# Conflicts:
#	remote-wallet/src/ledger.rs

* remote-wallet: `derivation-path` crate doesn't like empty trailing child indexes

(cherry picked from commit 4ce4f04c58)

* remote-wallet: Move `Locator` to its own module

(cherry picked from commit cac666d035)

Co-authored-by: Trent Nelson <trent@solana.com>

programs/bpf/Cargo.lock

@@ -2021,6 +2021,15 @@ dependencies = [
  "unicode-xid 0.2.0",
 ]
 
+[[package]]
+name = "qstring"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d464fae65fff2680baf48019211ce37aaec0c78e9264c84a3e484717f965104e"
+dependencies = [
+ "percent-encoding",
+]
+
 [[package]]
 name = "quote"
 version = "0.6.13"
@@ -3238,10 +3247,11 @@ dependencies = [
  "num-derive 0.3.0",
  "num-traits",
  "parking_lot 0.10.2",
+ "qstring",
  "semver 0.9.0",
  "solana-sdk",
  "thiserror",
- "url",
+ "uriparse",
 ]
 
 [[package]]