feat: make it possible to set disable_response_storage = true in config.toml (#714)

https://github.com/openai/codex/pull/642 introduced support for the
`--disable-response-storage` flag, but if you are a ZDR customer, it is
tedious to set this every time, so this PR makes it possible to set this
once in `config.toml` and be done with it.

Incidentally, this tidies things up such that now `init_codex()` takes
only one parameter: `Config`.

codex-rs/tui/src/app.rs

@@ -37,7 +37,6 @@ impl App<'_> {
         initial_prompt: Option<String>,
         show_git_warning: bool,
         initial_images: Vec<std::path::PathBuf>,
-        disable_response_storage: bool,
     ) -> Self {
         let (app_event_tx, app_event_rx) = channel();
         let scroll_event_helper = ScrollEventHelper::new(app_event_tx.clone());
@@ -81,7 +80,6 @@ impl App<'_> {
             app_event_tx.clone(),
             initial_prompt.clone(),
             initial_images,
-            disable_response_storage,
         );
 
         let app_state = if show_git_warning {