Allow creating initially hidden controls in wxOSX/Cocoa.

Allow creating initially hidden controls in wxOSX/Cocoa.

If wxWindow is hidden before being really created, we must create the native
control hidden too. Not only this allows to create the controls initially
hidden, as intended, but it also avoids the wx and native visibility flags
from getting out of sync which results in many other problems.

Closes #11131.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61725 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775