Make a single re-usable banner component (#27412)

Release Notes:

- Fixed an issue where both the predict edit and git onboarding banners
would both show at the same time.

crates/workspace/src/workspace.rs

@@ -182,6 +182,7 @@ actions!(
         ToggleZoom,
         Unfollow,
         Welcome,
+        RestoreBanner,
     ]
 );