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/note_paths.js

@@ -50,6 +50,7 @@ const TPL = `
 export default class NotePathsWidget extends TabAwareWidget {
     doRender() {
         this.$widget = $(TPL);
+        this.contentSized();
 
         this.$currentPath = this.$widget.find('.current-path');
         this.$dropdown = this.$widget.find(".dropdown");