macos: add padded-notch option for macos-non-native-fullscreen

Finishes #378
Supercedes #4159

This adds a new enum value for `macos-non-native-fullscreen`:
`padded-notch`. This value will add padding to the top of the window to
account for the notch on applicable devices while still hiding the
menu.

This value is preferred over "visible-menu" by some people because for
screens without a notch, the window will take up the full height.

The plan in the future is that we may color the padded area when a notch
is present. In this commit it appears as transparent.

src/Surface.zig

@@ -4201,6 +4201,7 @@ pub fn performBindingAction(self: *Surface, action: input.Binding.Action) !bool
                 .false => .native,
                 .true => .macos_non_native,
                 .@"visible-menu" => .macos_non_native_visible_menu,
+                .@"padded-notch" => .macos_non_native_padded_notch,
             },
         ),