Created|Deleted refactoring

* refactors base attributes created and deleted into UserActionLogEntry foreign keys
* refactors all related queries and process logic
* fixes binding_on into binding_date in intervention/detail/view.html
* adds basic __str__ for some models
*

konova/models.py

@@ -14,6 +14,7 @@ from django.db import models
 
 from konova.enums import DeadlineTypeEnum
 from konova.settings import DEFAULT_SRID
+from user.models import UserActionLogEntry
 
 
 class UuidModel(models.Model):
@@ -33,8 +34,9 @@ class BaseResource(UuidModel):
     """
     A basic resource model, which defines attributes for every derived model
     """
-    created_on = models.DateTimeField(auto_now_add=True, null=True)
-    created_by = models.ForeignKey(User, null=True, on_delete=models.SET_NULL, related_name="+")
+    created = models.ForeignKey(UserActionLogEntry, on_delete=models.SET_NULL, null=True, blank=True, related_name='+')
+    #created_on = models.DateTimeField(auto_now_add=True, null=True)
+    #created_by = models.ForeignKey(User, null=True, on_delete=models.SET_NULL, related_name="+")
 
     class Meta:
         abstract = True
@@ -48,8 +50,9 @@ class BaseObject(BaseResource):
     """
     identifier = models.CharField(max_length=1000, null=True, blank=True)
     title = models.CharField(max_length=1000, null=True, blank=True)
-    deleted_on = models.DateTimeField(null=True, blank=True)
-    deleted_by = models.ForeignKey(User, null=True, blank=True, on_delete=models.SET_NULL, related_name="+")
+    deleted = models.ForeignKey(UserActionLogEntry, on_delete=models.SET_NULL, null=True, blank=True, related_name='+')
+    #deleted_on = models.DateTimeField(null=True, blank=True)
+    #deleted_by = models.ForeignKey(User, null=True, blank=True, on_delete=models.SET_NULL, related_name="+")
     comment = models.TextField(null=True, blank=True)
 
     class Meta: