Update LED Widget for Telemetry Monitoring to Indicate Stale State

[henrydix]

Request:
While the ValueWidget currently provides a coloring indication of stale telemetry values, The LED Widget does not. In cases where LED widgets by themselves are used to indicate the state of a given telemetry point, there's no clear indication of whether or not that state is stale.

• We would like to request an enhancement to this widget such that the color of the LED light is turned slightly gray when the telemetry point it is tied to goes stale. This way, the viewer can still observe the current state, as well as whether or not that state is stale.