lok: avoid expensive fetching of a property.

lok: avoid expensive fetching of a property.

--doc_setView
   SfxLokHelper::setView
   SfxViewFrame::MakeActive_Impl
   SfxApplication::SetViewFrame_Impl
   |
    --SfxDispatcher::Update_Impl
              |
               --SfxWorkWindow::UpdateObjectBars_Impl
	         SfxWorkWindow::UpdateObjectBars_Impl2
		 |
		  --framework::LayoutManager::requestElement
                    framework::LayoutManager::createElement
                    |
                    --11.97%--framework::implts_isPreviewModel

We re-calculate the calc print-area on every setView via this
code-path; pointlessly expensive.

Change-Id: I36dbdc60a789fac4e2a82825b145725a4a4d6439
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/109805
Tested-by: Jenkins
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>