Do not automatically mark all text items as accessible.

This adds more confusion and fails more often due
to invisible items and overlays that it helps.
The test saw lots of "children" before that were
text elements, these are gone now.

With this the hack to make children based on
item role invisible can go away.

Change-Id: Ic5a3bba6e271747237e0e85168f4290bf596bc8a
Reviewed-by: Jan-Arve Sæther <jan-arve.saether@nokia.com>