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/global_menu.js

@@ -104,6 +104,7 @@ const TPL = `
 export default class GlobalMenuWidget extends BasicWidget {
     doRender() {
         this.$widget = $(TPL);
+        this.contentSized();
 
         this.$widget.find(".show-about-dialog-button").on('click',
             () => import("../dialogs/about.js").then(d => d.showDialog()));