Use getConfig on the viewer to retrieve state

[bnmajor]

Looking at the getConfig option it seems it doesn't contain a lot of the data that we would need to update the state

{
    "uiMachineOptions": "reference",
    "viewerConfigVersion": "0.3",
    "xyLowerLeft": false,
    "renderingViewContainerStyle": {
        "position": "relative",
        "width": "100%",
        "height": "auto",
        "minHeight": "200px",
        "minWidth": "450px",
        "margin": "0",
        "padding": "0",
        "top": "0",
        "left": "0",
        "flex": "1 1 0px",
        "overflow": "hidden"
    },
    "uiCollapsed": false,
    "main": {
        "backgroundColor": [
            0.5,
            0.5,
            0.5
        ],
        "units": ""
    }
}