When first node on a page is a section, then creation of a copy with
lcl_CreateWorkingDocument initially produces a document with layout
frames having wrong page descriptions applied (set to "Default Style").
The reason is that when SfxViewFrame::LoadHiddenDocument indirectly
calls SwRootFrame::Init, the sections in the document have hidden
flag set, which causes SwNodes::GoNextSection return the first node
after the first section. The returned node naturally doesn't have a
page description set, thus the initialized page frame doesn't get it.

This makes following copy to destination document use that wrong style;
if the correct page style had header/footer, then it would not be
properly copied per record in single-document output; headers/footers
would be wrong/absent.

This change forces check of page descriptions after the work document
had been created and initialized.

Change-Id: Ic196eb7fac0241f002eddd2c1d1b66dfb489bc60
Reviewed-on: https://gerrit.libreoffice.org/65383Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Tested-by: Mike Kaganski <mike.kaganski@collabora.com>