Swap overlay order of selection & hover outlines (#1705)

This causes selected things to no longer to be overwritten by hover outlines - Fixes #1597.

crates/re_viewer/src/misc/selection_state.rs

@@ -335,12 +335,12 @@ impl SelectionState {
         let mut next_selection_mask = || {
             // We don't expect to overflow u8, but if we do, don't use the "background mask".
             selection_mask_index = selection_mask_index.wrapping_add(1).at_least(1);
-            OutlineMaskPreference::some(selection_mask_index, 0)
+            OutlineMaskPreference::some(0, selection_mask_index)
         };
         let mut next_hover_mask = || {
             // We don't expect to overflow u8, but if we do, don't use the "background mask".
             hover_mask_index = hover_mask_index.wrapping_add(1).at_least(1);
-            OutlineMaskPreference::some(0, hover_mask_index)
+            OutlineMaskPreference::some(hover_mask_index, 0)
         };
 
         for current_selection in self.selection.iter() {

crates/re_viewer/src/ui/view_spatial/ui.rs

@@ -605,7 +605,7 @@ pub fn outline_config(gui_ctx: &egui::Context) -> OutlineConfig {
 
     OutlineConfig {
         outline_radius_pixel: (gui_ctx.pixels_per_point() * 1.5).at_least(0.5),
-        color_layer_a: selection_outline_color,
-        color_layer_b: hover_outline_color,
+        color_layer_a: hover_outline_color,
+        color_layer_b: selection_outline_color,
     }
 }