Resolve "When removing one of the network elements a wrong one got removed"

Description

See issue for description of the bug. There was a parameter missing or rather wrongly used in our code when calling the delete on the database, but it worked for the driver/db. The default behaviour there was deleting the first entry of the collection...

Related Issue

#263

controller/nucleus/databaseNetworkElementStore.go

@@ -251,7 +251,8 @@ func (s *DatabaseNetworkElementStore) Delete(networkElementToDelete networkeleme
 
 	db := client.Database(database.DatabaseName)
 	collection := db.Collection(s.storeName)
-	_, err = collection.DeleteOne(ctx, bson.D{primitive.E{Key: networkElementToDelete.ID().String()}})
+
+	_, err = collection.DeleteOne(ctx, bson.D{primitive.E{Key: "_id", Value: networkElementToDelete.ID().String()}})
 	if err != nil {
 		return customerrs.CouldNotDeleteError{Identifier: networkElementToDelete.ID(), Type: networkElementToDelete, Err: err}
 	}