debugger: First slight pass at UI (#27034)

- Collapse Launch and Attach into a single split button
- Fix code actions indicator being colored red.

Release Notes:

- N/A

crates/ui/src/components/button.rs

@@ -2,9 +2,11 @@ mod button;
 mod button_icon;
 mod button_like;
 mod icon_button;
+mod split_button;
 mod toggle_button;
 
 pub use button::*;
 pub use button_like::*;
 pub use icon_button::*;
+pub use split_button::*;
 pub use toggle_button::*;