Add hover to Extras ExpandableListItem
Don't change currentIndex on hover, instead just hover them. Show a subtler highlight for hover.
This solves the problem immediately for applets using ExpandableListItem. But applets using PC2 ListItem (like Clipboard) need to be ported away.
I didn't do it for PlasmaExtras ListItem since it needs the KF6 TODO marked there to be resolved first.
Edited by Bharadwaj Raju