The AttributedString that value or attributedValue will become after
a SemanticsAction.increase action has been performed on this widget.
If a attributedIncreasedValue is provided, onIncrease must also be set
and there must either be an ambient Directionality or an explicit
textDirection must be provided.
Callers must not provide both increasedValue and
attributedIncreasedValue, One or both must be null.
final AttributedString? attributedIncreasedValue;