Remove Accessible.description set on Action

the Accessible property only works for objects that inherit from Item.
Action inherits from QtObject, so setting Accessible.description on it
unfortunately does not work and instead just generates log error
messages.

PlasmaExtras.ExpandableListItem only allows you to set an action to
customize the default button, and doesn't expose the button object
itself, which is where accessibility properties would need to be set. So
this will require some refactoring to work properly.

CCMAIL: qydwhotmail@gmail.com

BUG: 463004
FIXED-IN: 5.27