many changes related to #1192:

- use CSS contain wherever possible to reduce subtrees of forced reflows
- reduced dependency between note and note_contents updates which will reduce number of updates to components
- optimization of "many rows" querying

src/public/app/widgets/standard_top_widget.js

@@ -10,6 +10,7 @@ const TPL = `
         display: flex;
         align-items: center;
         padding-top: 4px;
+        height: 35px;
     }
     
     .standard-top-widget button {
@@ -87,4 +88,4 @@ export default class StandardTopWidget extends BasicWidget {
         this.$enterProtectedSessionButton.hide();
         this.$leaveProtectedSessionButton.show();
     }
-}
+}