Add gsio-client and gsio-wallet crates with initial implementations

- Introduced `gsio-client` crate for interacting with GSIO nodes, including ledger entry management and node discovery.
- Introduced `gsio-wallet` crate for key management, transaction creation, and wallet functionality.
- Updated workspace configuration to include new crates.

Cargo.toml

@@ -1,5 +1,7 @@
 [workspace]
 members = [
     "crates/gsio-relay",
-    'crates/gsio-node'
-]
+    'crates/gsio-node',
+    "crates/gsio-client",
+    "crates/gsio-wallet"
+]