Fixed bug #75617 by loading folder contents when clicking them.
Fixed bug #75617 by removing manual load of folder contents and letting AsyncTreeNode handling that.
Fixed bug #80116. We prevent sharing of ids between folders and layers, which made the tree's selection model select layers of the same id as the folder that the user tried to expand.
The load button's disabled property is always set when showing the dialog. This prevents some inconsistencies.
Fixed bug #76449 together with persistence-geo commit b6f1afd4590ef54165eb1bd722088f4d5e95719d.