[Notebook] Save snapshot dropdown should be available from "view large" overlay #2922 (#2926)

* [Notebook] Save snapshot dropdown should be available from "view large" overlay #2922\
* Significant improvements to Snapshot styling
* [Notebook] Embed links aren't navigating #2979

Co-authored-by: charlesh88 <charlesh88@gmail.com>
Co-authored-by: Andrew Henry <akhenry@gmail.com>

src/ui/components/object-frame.scss

@@ -23,9 +23,12 @@
     }
 
     &:not(.c-so-view--no-frame) {
-        background: $colorBodyBg;
         border: $browseFrameBorder;
         padding: $interiorMargin;
+
+        .is-editing & {
+            background: rgba($colorBodyBg, 0.8);
+        }
     }
 
     &--no-frame {