Re-enable website background updates

[stronk-dev]

In order to prevent the site from stuttering when we get events in the background:
on backend store store if a user has stale data or not
when we get data, set flag to having fresh data
whenever a new event of that type comes in, mark all as stale

on frontend, add a second backgroundRefresh getter, call this maybe every 10 seconds
backend only returns new data if the data is stale, else it returns a special signal
dont forget to market data as fresh
frontend ignores when not receiving new data

[stronk-dev]

Working for Events and monthly stats