ItemDelegate: set icon's selected: property appropriately
Otherwise symbolic icons won't change their colors when their list items are highlighted or pressed.
Found this while investigating why the icons in Elisa's view selector sidebar don't change color appropriately:
This patch alone is not enough to fix the issue, which suggests an additional issue in Kirigami.Icon somewhere. I looked briefly but couldn't find anything obviously wrong.
Still, this change seems correct even if it's not sufficient to fix the issue alone.
Edited by Nate Graham