Work around broken wxWindow::SetId() in wxMSW 3.0 in XRC code.

As wxWindow::SetId() doesn't update the ID at the Windows level in 3.0 and
can't be modified to do it because of ABI compatibility concerns, work around
this in the code calling SetId() in XRC wxUnknownControlContainer itself.

Closes #3697.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76670 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775