#2671 ttk::entry looses state invalid at focus events

Platforms: Unix X11 and Windows

Example to reproduce
% pack .e
% bind .e <FocusIn> {puts "%W <FocusIn> %d: [.e state]"}
% bind .e <FocusOut> {puts "%W <FocusOut> %d: [.e state]"}
% bind .e <Return> {.e state invalid}

After pressing Return inside the field and focussing outside the entryfield,
the state invalid is lost.
It also happens if you set state invalid from the console and focus into the entryfield.