fdo#71720 Add Excel 2010 functions

CEILING.PRECISE, ISO.CEILING, FLOOR.PRECISE

Change-Id: I047b65ca3adafb89fce9b6493948aa851ddca765
Reviewed-on: https://gerrit.libreoffice.org/8488
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>