ListItem should respond to touch

[ykami]

ListItem (and other _ItemBase-based widgets) should be highlighted when the user touches it. The operation should be able to be canceled if the user drags a finger a little. To achieve this, touch events have to be handled instead of click events.

[ykami]

In [27598]:

Refs #14604 !strict. Use touchstart/touchmove/touchend instead of onclick to handle user's select operation. Some widget may want to invoke the action on touchstart. Some others may want to invoke it on touchend. This module supports such various cases.

[ykami]

In [27619]:

Refs #14604 !strict. ListItem? responds to user's touch operation and changes to the selected color immediately. The color is restored after a little while. The action is invoked on touch-end. Also, deleteIcon was added.

[bill]

In [28275]:

Manually generate click event from touchend event to avoid iOS/safari bugs when a click event doesn't occur after focus has been programatically shifted.

Right now the code is just listening for touchend events. dojox/mobile is doing something more complicated where it listens to touchstart, touchmove, and touchend. That's not needed on most dijit pages since touchmove just scrolls the document, while keeping the finger on the originally touched node. But maybe dijit will need to do it eventually for pages that trap touchmove and call evt.preventDefault(), thus allowing a user to touchstart somewhere random, slide to the node with the a11yclick handler, and then do a touchend.

Fixes #14918, refs #14604 !strict.