feat: add flag for link line visiable for Transformer's rotate

[liulinboyi]

Hide the line of the Konva rotation handle and keep the rotation function.

Resolve the #1688.

var rect = new Konva.Rect({
  x: 100,
  y: 100,
  width: 200,
  height: 200,
  fill: "pink",
  draggable: true
});

var tr = new Konva.Transformer({
  nodes: [rect ],
  anchorSize: 10,
  rotateLinkLineVisiable: false, // add this flag to hide the link line
});

The rotateLinkLineVisiable's default value is true, when the value is false will be like the follow:

[lavrton]

I changed the attribute name a little. Thanks for the PR.

[liulinboyi]

I changed the attribute name a little. Thanks for the PR.

Cool!