a11y: Fix AdwEntryRow accessibility, again
The previous approach unfortunately could work only for widgets where the GtkText child a direct child of the textbox widget. If we would want to keep this approach, we'd have to reimplement GtkAccessible on the gizmo, not the ListboxRow. To simplify things, give the text_box role to the text control, the user can not focus any other part of the widget anyway, and remove the GtkAccessible override, as it is not needed now. This, finally, fixes gtk#5162 (closed)
Edited by Lukáš Tyrychtr