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/layouts/desktop_main_window_layout.js

@@ -110,6 +110,7 @@ export default class DesktopMainWindowLayout {
             .id('root-widget')
             .css('height', '100vh')
             .child(new FlexContainer('row')
+                .css('height', '35px')
                 .child(new GlobalMenuWidget())
                 .child(new TabRowWidget())
                 .child(new TitleBarButtonsWidget()))
@@ -130,6 +131,7 @@ export default class DesktopMainWindowLayout {
                 .child(new FlexContainer('column').id('center-pane')
                     .child(new FlexContainer('row').class('title-row')
                         .cssBlock('.title-row > * { margin: 5px; }')
+                        .css('height', '55px')
                         .child(new NoteTitleWidget())
                         .child(new RunScriptButtonsWidget().hideInZenMode())
                         .child(new NoteTypeWidget().hideInZenMode())