Populate citation reference properties.

src/types/object.rs

@@ -209,6 +209,9 @@ pub struct Citation<'s> {
 #[derive(Debug, PartialEq)]
 pub struct CitationReference<'s> {
     pub source: &'s str,
+    pub key: &'s str,
+    pub prefix: Vec<Object<'s>>,
+    pub suffix: Vec<Object<'s>>,
 }
 
 #[derive(Debug, PartialEq)]