Support for momentary mode a la UISegmentedControl

[dwag3]

It would be great if momentary selection were supported, ie, the selected segment reverts to unselected once the touch event has ended.

https://developer.apple.com/documentation/uikit/uisegmentedcontrol/1618586-momentary

[sima-11]

@dwag3 That's a good idea. Thanks! Will try to add it in the next release. May take a while though. :)