hidden and in all other cases it was set by the implementing control, i.e.
the label was not reusable, hence no reason to have it in the control and risk
layout issues. This means that the SrPicker does not need to be a control
encapsulating a CustomTreeVIew, but simply derive from the latter.
Signed-off-by: Konstantina Chremmou <konstantina.chremmou@citrix.com>