Remove all references to QAccessible:: {Child|Ancestor|Sibling}

Remove all references to QAccessible:: {Child|Ancestor|Sibling}

These are deprecated in favor of
QAccessibleInterface::child() and QAccessibleInterface::parent()

QAccessible::Sibling can be done with a combination of those two.
This is handled by the bridge

Change-Id: Ie63d74314189d9e0f24f1152a2f0030d9e865b75
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@nokia.com>