Misc UI bug fixes

[mcartmel]

No description provided.

[justparking]

Hey @scroix and @thefennecdeer - do you mind doing a quick review of the changes in case you spot something that might cause an issue?

My only concern is this part:

// proactively disconnect websocket when the page is not being viewed

If it means it readily disconnects and reconnects the websocket, it might have a noticable effect flipping between browser tabs (and in particular, those hosting large dashboards/frontend). I know that the websocket code syncs up the state of all events every time it connects.

I've put this to @mcartmel already.

[scroix]

I'll take a look and report back 🫡

[scroix]

No immediate issues with the dashboard updating across multiple devices/browsers, but I don't have the scale that @thefennecdeer would be dealing with.

@justparking, I did have a bit of trouble running the binary on Java 8. I can't recall whether we were enforcing Java 11 now. It might've just been my IDE settings overriding our Gradle rules for compatible builds.