Fix #1230: List: Add Edge UA sniff to dom-rtl-scrollbar-left test
Fix #1230: List: Add Edge UA sniff to dom-rtl-scrollbar-left test

Unfortunately, IE and Edge both report offsetLeft as 0 in this feature
detect, while other browsers report a value that reflects whether the
scrollbar is to the left.  Without any other conceivable way of actually
detecting this for IE/Edge, we have no choice but to add another UA sniff.

dylans/dgrid,kfranqueiro/dgrid,dylans/dgrid,maier49/dgrid,kfranqueiro/dgrid,maier49/dgrid,kfranqueiro/dgrid,maier49/dgrid,dylans/dgrid