Arrays of nested Widgets with conditional render logic are output in the wrong order

[agubler]

Bug

In scenarios where there are multiple children of nested virtual widgets that conditionally render their output based on their properties the resulting DOM can be attached in the incorrect order. This only happens when the parent nested widgets invalidate in the sub tree and not within the same scheduled render (i.e. waiting for independent server side responses).

It seems to be caused by not being able to identify the top level dom node of the nested widget to insert before when rendering the DOM in from the first widget.