#50 Overlaying geometries

* refactors geometry field into GeoReferencedMixin, holding more handy methods and used in all models, formerly holding the geometry field
* refactors backend admin configuration, so modified, deleted and created are not editable in the backend which also skips loading of all possible choices
* fixes typo in sanitize_db command
* introduces GeometryConflict model, holding a link between two geometries, where one overlaps the other
* adds first (WIP) messages into detail views of ema and intervention for test purposes

konova/admin.py

@@ -7,7 +7,7 @@ Created on: 22.07.21
 """
 from django.contrib import admin
 
-from konova.models import Geometry, Deadline
+from konova.models import Geometry, Deadline, GeometryConflict
 
 
 class GeometryAdmin(admin.ModelAdmin):
@@ -17,6 +17,14 @@ class GeometryAdmin(admin.ModelAdmin):
     ]
 
 
+class GeometryConflictAdmin(admin.ModelAdmin):
+    list_display = [
+        "conflicting_geometry",
+        "existing_geometry",
+        "detected_on",
+    ]
+
+
 class AbstractDocumentAdmin(admin.ModelAdmin):
     list_display = [
         "id",
@@ -35,5 +43,14 @@ class DeadlineAdmin(admin.ModelAdmin):
     ]
 
 
+class BaseObjectAdmin(admin.ModelAdmin):
+    readonly_fields = [
+        "modified",
+        "deleted",
+        "created",
+    ]
+
+
 admin.site.register(Geometry, GeometryAdmin)
+admin.site.register(GeometryConflict, GeometryConflictAdmin)
 admin.site.register(Deadline, DeadlineAdmin)