Add YAMCS Clock Widget

[lorenzo-gomez-windhover]

Could be very useful for flight tests

[lorenzo-gomez-windhover]

Possible place to start: https://github.com/WindhoverLabs/phoebus/blob/26a232f88067e8824f3ccd29086af664b5545cd7/app/display/model/src/main/java/org/csstudio/display/builder/model/widgets/ClockWidget.java