Display latest occurrences panel on disease extent layer

Each AdminUnitDiseaseExtentClass needs the list of (up to) 5 latest disease occurrences that were used in determining its class (presence etc), so that they are included when converting to GeoJsonDiseaseExtentFeatureProperties. The AUDEC id lives on the DO table in DB, but the relationship on Java-side is represented by a List<DO> on the AUDEC class.