feat: Better Server Error Fallbacks

[Mitsunee]

the UpgradesPage and EventsPage routes currently just disappear entirely if there's server errors (such as today when there were issues at aws). UpgradesPage could probably just display the error message in the already existing section, replacing the search and filters, while EventsPage would have to create a new section.

While this is getting adressed it'd also be good to add a loading indicator on EventsPage as well as making the search field not pre-render as it is useless without javascript. It's probably good enough to start displaying it after data fetching completed instead.