Add text element metadata to types (#9235)

Initial type tweaking PR to make the diff of
https://github.com/openai/codex/pull/9116 smaller

This should not change any behavior, just adds some fields to types

codex-rs/app-server/tests/suite/v2/turn_interrupt.rs

@@ -73,6 +73,7 @@ async fn turn_interrupt_aborts_running_turn() -> Result<()> {
             thread_id: thread.id.clone(),
             input: vec![V2UserInput::Text {
                 text: "run sleep".to_string(),
+                text_elements: Vec::new(),
             }],
             cwd: Some(working_directory.clone()),
             ..Default::default()