refs #15135 [master] kxp id retrieval

* adds getKxpId() to RecordDriver

module/finc/src/finc/RecordDriver/SolrDefaultFincTrait.php

@@ -1278,4 +1278,15 @@ trait SolrDefaultFincTrait
         return isset($this->fields['facet_avail'])
             ? $this->fields['facet_avail'] : [];
     }
+
+    /**
+     * Get K10Plus PPN for this record
+     * This will be stored in 'kxp_id_str'
+     *
+     * @return array
+     */
+    public function getKxpId() {
+        return isset($this->fields['kxp_id_str'])
+            ? $this->fields['kxp_id_str'] : [];
+    }
 }