Add streaming support for the responses API (#5)

* add stream flag to req body

* stub

* add streaming response

Author: masci

Cargo.lock

@@ -29,6 +29,8 @@ colored = "2"
 
 tower = { version = "0.4", features = ["full"] }
 tower-http = { version = "0.5", features = ["timeout"] }
+futures-util = "0.3"
+async-stream = "0.3"
 
 [dev-dependencies]
 tempfile = "3.20.0"