Improve various loading states #257
Description
There are bunch of issues with how loading data works currently.
- Initial load takes a while since its a lot of data
- I'm storing selected source in cookies and local storage which is a pain
- When hovering over the different pages, for some reason sveltekit invalidates the layout route and re-downloads like all the static data again (This only seems to happen when a current_time is specified).
- Sometimes on initial load, none of the realtime data is loaded in and it shows no trips.