Dashboard improvements

[manuelmeister]

Continuation from #3150

• Skeleton loader for the table
• Persist the filters in the URL, for sharing filtered lists and so that when navigating to an activity and back, the same filters are restored Persist dashboard filters in query params #3406
• Days should not be loaded with individual network requests when navigating to the dashboard from another page
• Simplify durations (removing 0min when it's only 2h 0min)
• Distinguish clear in SelectFilter from other options

[carlobeltrame]

Most of this was already included in #3150.

The days loading issue I could not reproduce. @usu does this really still happen? Can you provide a way to reproduce it?

Other than that, this issue more or less becomes an issue to discuss how to store the filters. We could store it in the URL, but it would get quite long because we use URIs, not ids now. Or we could store it in the Vuex store, but then it would get lost when reloading the page, and the filtered list wouldn't be shareable by link.

[usu]

The days loading issue I could not reproduce. @usu does this really still happen? Can you provide a way to reproduce it?

Yes, I can consistently reproduce. Adressed in #3158
When I load the dashboard directly, a network request to /camps/123 is made, which comes with a lot of embedded data. When I navigate from /camps to the the dashboard, no such request is made because the camp is already known. But then days and campCollaborations are unknown and hence loaded with separate requests.

[BacLuc]

seems to be better