[Dashboard Screeen] - "Disable" the LED (widget) when the time for "Show Offline" expires

[georgevbsantiago]

With the implementation of "Show Offline" in the widgets, it would be important to define a state (color) for the LED widget to inform when the device is offline (or the bucket stops receiving data/uplinks), instead of informing the payload of the last uplink.

In the example below, the LED is gray to represent that the Device is Offline (or the bucket stops receiving data/uplinks) (Time overrun for "Show Offline").

This implementation will improve the experience of users analyzing Dashboard information and data.

This functionality follows the same logic as the suggestion made in the issue: [Dashboard Screeen] - The button does not disable when the device is offline