fdo#71076, fdo#71767: Preserve number formats when charts are copied.

(cherry picked from commit 1d38cb365543924f9c50014e6b2227e77de1d0c9)

Conflicts:
	sd/source/ui/view/sdview3.cxx
	xmloff/source/chart/SchXMLExport.cxx

Change-Id: If5ae8852152012483237e7602e56a0c46ea8748a
Reviewed-on: https://gerrit.libreoffice.org/9836
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>