UI: tweak display of active, selected and edited items in the outliner

* Change circle to roundbox around active icons, so they don't overflow.
* Change text color to indicate selected and active state.

Differential Revision: https://developer.blender.org/D4650

release/scripts/presets/interface_theme/blender_light.xml

@@ -983,6 +983,9 @@
       <ThemeOutliner
         match="#337f33"
         selected_highlight="#314e78"
+        selected_object="#9a3900ff"
+        active_object="#7e4f14ff"
+        edited_object="#ffad4560"
         row_alternate="#3f3f3f1a"
         >
         <space>