Translate German variable names in Calc (financial)

As in https://gerrit.libreoffice.org/43987

This is for string literals only. Variables and functions like "nKorrValDecl"
and "GetRmz" will be translated on a separate, later Gerrit change.

Change-Id: I86c163f40bc13c800315f426f5815d141853644b
Reviewed-on: https://gerrit.libreoffice.org/44295Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Eike Rathke <erack@redhat.com>