QtIFW

Fix select state for unstable components

In updater mode, unstable components needs to be unselected so that
those won't be updated. In packagemanager mode, installed unstable
components needs to be in checked state so that those won't be
uninstalled.

Change-Id: Ib3d16ae8c0eec4e07731a0082c02fd710ffdb9d6
Reviewed-by: Iikka Eklund <iikka.eklund@qt.io>