A view model that represents each item in the BaseLayerPicker
alias ProviderViewModel
{Object} options The object containing all parameters.
{String} options.name The name of the layer.
{String} options.tooltip The tooltip to show when the item is moused over.
{String} options.iconUrl An icon representing the layer.
{ProviderViewModel~CreationFunction|Command} options.creationFunction A function or Command
that creates one or more providers which will be added to the globe when this item is selected.
A view model that represents each item in the BaseLayerPicker
alias ProviderViewModel
TerrainProvider
ImageryProvider
BaseLayerPicker