Fixes for calling Enable() on children of a disabled TLW in wxMSW.

Fixes for calling Enable() on children of a disabled TLW in wxMSW.

The change of the child window state wasn't reflected immediately if it was
done while the TLW itself was disabled but only happened when it was
reenabled and in some cases the child could not be enabled even then.

Fix this by updating the child state immediately, even when its TLW parent is
disabled and only skip the update of the children state when TLW is being
disabled, not when it's enabled back.

Closes #11622.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65864 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775