feat: show MCP tool calls in codex exec subcommand (#841)

This is analogous to the change for the TUI in
https://github.com/openai/codex/pull/836, but for `codex exec`.

To test, I ran:

```
cargo run --bin codex-exec -- 'what is the weather in wellesley ma tomorrow'
```

and saw:


![image](https://github.com/user-attachments/assets/5714e07f-88c7-4dd9-aa0d-be54c1670533)

codex-rs/exec/Cargo.toml

@@ -16,7 +16,9 @@ anyhow = "1"
 chrono = "0.4.40"
 clap = { version = "4", features = ["derive"] }
 codex-core = { path = "../core", features = ["cli"] }
+mcp-types = { path = "../mcp-types" }
 owo-colors = "4.2.0"
+serde_json = "1"
 shlex = "1.3.0"
 tokio = { version = "1", features = [
     "io-std",