containments/desktop: resolve binding loop.
The assignment of minimum and preferred sizes on the FolderView has binding loops, which result from intermediate values as the other bindings are filled.
This change resolves these loops by setting the bindings using Qt.callLater(); when the main loop is clear and the other bindings have settled, the proper sizes can be determined without causing loops.
BUG: 483859
Edited by Christoph Wolk