Gets the value of a single-valued VCardAttribute, this .
For example, for a <code>FN</code> (full name) attribute, this will return the contact’s full name as a single string.
This will print a warning if called on an VCardAttribute which is not single-valued ( i.e. for which is_single_valued returns false). Use get_values in such cases instead.
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A newly allocated string representing the value, or null if the attribute has no value. |