Move approvals to use ListSelectionView (#4275)

Unify selection menus:
- Move approvals to the vertical menu `ListSelectionView`
- Add header section to `ListSelectionView`

<img width="502" height="214" alt="image"
src="https://github.com/user-attachments/assets/f4b43ddf-3549-403c-ad9e-a523688714e4"
/>

<img width="748" height="214" alt="image"
src="https://github.com/user-attachments/assets/f94ac7b5-dc94-4dc0-a1df-7a8e3ba2453b"
/>

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Co-authored-by: pakrym-oai <pakrym@openai.com>

codex-rs/tui/src/chatwidget.rs

@@ -84,7 +84,7 @@ use crate::slash_command::SlashCommand;
 use crate::text_formatting::truncate_text;
 use crate::tui::FrameRequester;
 // streaming internals are provided by crate::streaming and crate::markdown_stream
-use crate::user_approval_widget::ApprovalRequest;
+use crate::bottom_pane::ApprovalRequest;
 mod interrupts;
 use self::interrupts::InterruptManager;
 mod agent;