New Reports: Add an expand/collapse all option (edited)

Absolutely love the new reports beta formatting. It would be great if there were a way to expand/collapse all categories and/or subcategories at once. Bonus if the degree to which it was expanded/collapsed was remembered between sessions (like how it remembers the selected date range between sessions).

Currently, it defaults to all categories, subcategories, and individual transactions fully expanded. I most commonly want to reports to show subcategory totals, so I have to collapse dozens of categories individually every time I visit the page. It takes dozens of clicks to collapse each one individually. Just a minor nitpick for a great new feature.