IssueTracker

After researching how it works in similar frameworks we decided we don't want to use the RenderNode's build in drawing reordering based on the elevation and want to keep using elevations only as a shadow size. With introducing such modifiers we will be able to easily reorder children without forcing to change the shadow size as will(it will be obviously easy to add both Z index modifier and draw shadow modifier with the same value if it is needed).