Add new columns to BillingEvent (#1573)

* Add new columns to BillingEvent.java

* Improve PR and modifyJodaMoneyType to handle null currency in override

* Add test cases for edge cases of nullSafeGet in JodaMoneyType

* Improve assertions

db/src/main/resources/sql/schema/db-schema.sql.generated

@@ -79,6 +79,9 @@
         domain_name text not null,
         recurrence_end_time timestamptz,
         recurrence_time_of_year text,
+        renewal_price_amount numeric(19, 2),
+        renewal_price_currency text,
+        renewal_price_behavior text not null,
         primary key (billing_recurrence_id)
     );