Improve page title handling

[elstoc]

Page title is set based on a useEffect hook that will only fire if the props of a component change. However, if a sub-component attempts to override the title of a higher-level component, and is then unmounted, the higher-level useEffect won't necessarily re-fire and update the title to its previous value.

[elstoc]

Perhaps a global context with the page title is the best way to do it