#31 API basic implementation EcoAccount fetch

* outsources json creation of modified_on an created_on to superclass
* adds API support for fetching ecoaccount data

api/views/v1/intervention.py

@@ -32,8 +32,6 @@ class APIInterventionViewV1(AbstractModelAPIViewV1):
         )
 
     def model_to_json(self, entry: Intervention):
-        modified_on = entry.modified or entry.created
-        modified_on = modified_on.timestamp
         entry_json = {
             "identifier": entry.identifier,
             "title": entry.title,
@@ -42,8 +40,8 @@ class APIInterventionViewV1(AbstractModelAPIViewV1):
             "compensations": self.compensations_to_json(entry.compensations.all()),
             "payments": self.payments_to_json(entry.payments.all()),
             "deductions": self.deductions_to_json(entry.deductions.all()),
-            "modified_on": modified_on,
-            "created_on": entry.created.timestamp,
+            "modified_on": self.modified_on_to_json(entry),
+            "created_on": self.created_on_to_json(entry),
         }
         geom = entry.geometry.geom.geojson
         geo_json = json.loads(geom)