feat: implement rest vertical slice

crates/mcpaas-adapter-rest/src/lib.rs

@@ -1,3 +1,7 @@
-pub fn crate_name() -> &'static str {
-    "mcpaas-adapter-rest"
-}
+mod client;
+mod error;
+mod model;
+
+pub use client::RestAdapter;
+pub use error::RestAdapterError;
+pub use model::{RestRequest, RestResponse};