Add support for constrainDimensions option

[Tylerian]

Context

Dragging an item without fixed dimensions exhibits weird behavior. This is a well known problem on the shopify/draggable library itself and it offers a constrainDimensions option just for that, but livewire-sortable has no way to specify that.

Solution

Add support for passing the constrainDimensions option to a sortable component by setting the wire:sortable.constrainDimensions attribute.