writerfilter: remove code duplication

Change-Id: I55dfeb9b0505bb5f46d5bcf98b10bd2ba7b187f9
fdo#73159 Make back border dialog work again

I removed border dialog with commit
8560fb88c7252e5ad60674e447f2e194298f08de
because it seems unused and when the corresponding
command was called only a blank window was opened.
It seems it was just bugous, so revert this commit
and fix the dialog.

Conflicts:
	sw/inc/swabstdlg.hxx
	sw/source/ui/dialog/swdlgfact.cxx
	sw/source/ui/dialog/swdlgfact.hxx

Change-Id: I68f8c13457e899a894f03bdd60ebedfb2b70afea