ResultDelegate: Make click on an entry work again

For some reason, `ListItem` is taking all the mouse events which do not reach the parent MouseArea.

Drag and drop is also not working because `onPressed()` and `onReleased()` are never triggered.

I guess that `PlasmaExtras.ListItem` is a different beast than its PC2 counterpart, and a larger refactor could help, even to simplify stuff.

(The inheritance chain goes `PlasmaExtras.ListItem` \> `Kirigami.AbstracListItem` \> `QQC2.DelegateItem` \> `QQC2.AbstractButton` \> `QQC2.Control`)

BUG: 472558