CLI BIP32 prep: KeypairUrl refactor (backport #16592) (#16605)

* clap-utils: Rename KeypairUrl to SignerSource

(cherry picked from commit 09dcc9ea04)

* clap-utils: Reduce SignerSource's visibility

(cherry picked from commit c5ab3ba6f1)

* clap-utils: Use `uriparse` crate to parse `SignerSource`

(cherry picked from commit 5d1ef5d01d)

* clap-utils: Add explicit schemes for `ask` and `file` `SignerSource`s

(cherry picked from commit 6444f0e57b)

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

programs/bpf/Cargo.lock

@@ -2949,6 +2949,7 @@ dependencies = [
  "solana-sdk",
  "thiserror",
  "tiny-bip39",
+ "uriparse",
  "url",
 ]
 
@@ -4111,6 +4112,16 @@ version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a156c684c91ea7d62626509bce3cb4e1d9ed5c4d978f7b4352658f96a4c26b4a"
 
+[[package]]
+name = "uriparse"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e515b1ada404168e145ac55afba3c42f04cf972201a8552d42e2abb17c1b7221"
+dependencies = [
+ "fnv",
+ "lazy_static",
+]
+
 [[package]]
 name = "url"
 version = "2.2.1"