Tag CatalogGroup needs to support other group type when displayGroup set to true

[mwu2018]

When the trait displayGroup set to true for wms-group type, the icon in the button is shown as x (Remove all) before being clicked on. Once the button is clicked, it becomes Add all icon -- unable to do Remove all.

See TerriaJS/nationalmap#1226 (comment)

The expected behaviour should be exactly opposite.

Tech Note
It has been found that props.allItemsLoaded passed to CatalogGroup is true before the group button is clicked, even if the workbench is empty.