Possibly switch React Router from declarative mode to data mode, to notify user when they leave a page with unsaved changes

[juhanikat]

More information about the React Router modes here: https://reactrouter.com/start/modes

Currently, the site does not show a confirmation before leaving a page if the user leaves by clicking a link in the top navigation bar, or by pressing the back button in their browser. This could be fixed by using useBlocker (https://reactrouter.com/api/hooks/useBlocker), but it seems like that hook can only be used if the React Router mode is switched for the entire application.