Maybe eventually we can get rid of attempts in LibreOffice to
interpret names as consisting of culture-dependent parts like "given
name", "father's name", "last name" etc and just treat names as opaque
strings. Let's start by saying explicitly that if "givenname" is empty
but "sn" is not, then "sn" is the full name.

See https://www.kalzumeus.com/2010/06/17/falsehoods-programmers-believe-about-names/

Change-Id: Id2c1df08c8faf65fd25d46a4380f5f53e60d5378