Maxym Borodenko authored May 27, 2021 and Matija Obreza committed May 31, 2021

- AuditLogFilter extends EmptyModelFilter;
- AuditLog extends EmptyModel;
- moved equals(), hashCode() and toString() from BasicModel to EmptyModel;
- ignoredClassFields and securedClassFields are synchronized;
- use __FIELD_VALUE_NOT_AUDITED__ instead of null when audited value must not be persisted