Web-UI Reconnect after Session Expiry is Broken

[nbauernfeind]

My setup is:

1. server on a remote host
2. connect via web-ui, run t = timeTable("PT1s") to get a ticking table on screen
3. attach a debugger to the remote JVM, wait out the session expiry (~5m)

The UI never notified me 1) the connection was lost / temporarily unavailable (the table just stopped ticking; no information at all), and 2) when I resume from the debugger the UI changes to Waiting for viewport... and 3) any REPL runs think they're successful but run indefinitely.

The session is lost and the web-client is a bit confused about that.

Note that this also exists in v0.36.1 and was not introduced by the jsapi refactoring(s).