fdo#69613: Code changes for TOC with flag '\w' should get preserved after RT.

Issue :
	TOC field flag '\w' was not getting preserved after RT.

Implementation :
	Provided import & export support for TOC field flag '\w'.

XML file difference :
In document.xml,

Before - <w:instrText>
		TOC \o "1-3" \h \z \w
	</w:instrText>

After - <w:instrText>
		TOC \w \o "1-3" \o "1-3" \h
	</w:instrText>

Conflicts:
	sw/inc/tox.hxx
	sw/inc/unomap.hxx
	sw/inc/unoprnms.hxx
	sw/source/core/unocore/unomap.cxx
	sw/source/filter/ww8/ww8atr.cxx
	sw/source/ui/index/cntex.cxx
	writerfilter/source/dmapper/DomainMapper_Impl.cxx
	writerfilter/source/dmapper/PropertyIds.cxx
	writerfilter/source/dmapper/PropertyIds.hxx
Reviewed on:
	https://gerrit.libreoffice.org/7238

Change-Id: Ia5d602c6db0b59933d325058ce2d8111e4f03df5