BHV-19184: Allow for continuation of scroll animation upon a tap.

### Issue
There are situations where we do not want the act of tapping on scrolling content to interrupt the current scroll animation.

### Fix
We add a property `tapToStop` to `enyo.ScrollStrategy` and facade this in `enyo.Scroller`.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>