Add info debug to datainput-controlled visibility changes

Element visibility can be hard to debug as there are several ways for an element to change visible state: datainput control, setAttribute and slide transitions.

Add INFO-level debug to following situations:

Datainput discards incoming value because it matches with the current value

Datainput takes persistent control over master slide element visibility (happens at the first setDataInputValue call)

Runtime skips master element element visibility setting at slide change, because master slide element has persistent datainput controller.

This helps detect situations where either datainput control, or slide change fails to change element visibility in expected manner.