The full name of the contact.
The full name is the name of the contact written in the way the contact prefers. For instance for English names this is usually the given name followed by the family name, but Chinese names are usually the family name followed by the given name. The full name could or could not contain additional names (like a middle name), prefixes or suffixes.
The full name must not be
null: the empty string represents an unset full name.