Show a warning symbol if server has not sent data in a while

[AuroraLS3]

I would like to be able to..

Quickly determine if something has gone wrong with a Plan instance / server on a network

Is your feature request related to a problem? Please describe.

One network was wondering why they hadn't gotten new data from one server for a week and it turned out the server was running Java 8 while the Plan version needed Java 11 and did not enable.

The website did not show clearly that Plan was not sending data. (Uptime was 'Unavailable' and 'Possibly offline' didn't really raise any alarm bells) There should be an exclamation triangle (possibly orange/yellow) that tells Plan hasn't received data from a server for a while.

Maximum date from plan_tps can be used to get last data sent date