Start CQRS refactoring: Create Osiris client crate

- Added workspace structure to Osiris Cargo.toml
- Created osiris-client crate for query operations (GET requests)
- Implemented generic get(), list(), query() methods
- Added KYC, payment, and communication query modules
- Created comprehensive refactoring plan document

CQRS Pattern:
- Commands (writes) → Supervisor client → Rhai scripts
- Queries (reads) → Osiris client → REST API

Next steps:
- Implement Osiris server with Axum
- Restructure SDK client by category (kyc/, payment/, etc.)
- Update FreezoneClient to use both supervisor and osiris clients

client/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "osiris-client"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+reqwest = { version = "0.11", features = ["json"] }
+anyhow = "1.0"
+thiserror = "1.0"
+
+[dev-dependencies]
+tokio = { version = "1.23", features = ["full", "macros"] }