New Map Viewer should link to layer's item details pages

[CatherineM]

In the new Map Viewer, under Properties > Information, there is a link to the layer's source. But for feature layers it links to the item details sublayer page, which is rarely used. 

This is confusing, and will prevent users finding important information in the item details. It should link to the main item details page instead, which it does for other layer types (e.g. imagery or group layers).

e.g. this Esri wetlands layer

links to this blank page - https://themetoffice.maps.arcgis.com/home/item.html?id=1f2cb14aa91b41efbd01d676a6e289b4&sublayer=0

instead of this useful one - https://themetoffice.maps.arcgis.com/home/item.html?id=1f2cb14aa91b41efbd01d676a6e289b4