Add codex apply to apply a patch created from the Codex remote agent (#1528)

In order to to this, I created a new `chatgpt` crate where we can put
any code that interacts directly with ChatGPT as opposed to the OpenAI
API. I added a disclaimer to the README for it that it should primarily
be modified by OpenAI employees.


https://github.com/user-attachments/assets/bb978e33-d2c9-4d8e-af28-c8c25b1988e8

codex-rs/chatgpt/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "codex-chatgpt"
+version = { workspace = true }
+edition = "2024"
+
+[lints]
+workspace = true
+
+[dependencies]
+anyhow = "1"
+clap = { version = "4", features = ["derive"] }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+codex-common = { path = "../common", features = ["cli"] }
+codex-core = { path = "../core" }
+codex-login = { path = "../login" }
+reqwest = { version = "0.12", features = ["json", "stream"] }
+tokio = { version = "1", features = ["full"] }
+
+[dev-dependencies]
+tempfile = "3"