resolved fdo#67536 export internal equivalents as add-in to .xls

For BIFF .xls export the internal functions that are equivalents of
known add-in functions as those add-in functions.

(cherry picked from commit 06a5b1ecc39bb50dadc0bcb7378455500943ece3)

Conflicts:
	sc/source/filter/inc/xlformula.hxx

Change-Id: If37f616a34fdabb3fa971fddad01da3dc1f28ee9
Reviewed-on: https://gerrit.libreoffice.org/6525
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>