Closes #19713: Enable recording user messages in the change log (#19908)

* Add message field to ObjectChange model

* Set max length on changelog message

* Enable changelog messages for single object operations

* Fix tests

* Add changelog message support for bulk edit & bulk delete

* Cosmetic improvements to form fields

* Fix bulk operation templates

* Add message support for bulk import/update

* Add REST API support for changelog messages (WIP)

* Fix changelog_message assignment

* Enable changelog message support for bulk deletions

* Add documentation

* Fix changelog message support for VirtualChassis

* Add ChangeLoggingMixin to necesssary model forms

* Introduce get_random_string() utility function for tests

* Incorporate changelog messages for object view tests

* Incorporate changelog messages for object bulk view tests

* Add missing mixins for changelog message support

* Tweak test to generate expected number of change records

* Finish adding tests for changelog message functionality

* Misc cleanup

* Fixes #19956: Prevent duplicate deletion records from cascading deletions

* Tweak bulk deletion test to work around cascading deletions issue

* Correct API URL

netbox/core/api/serializers_/change_logging.py

@@ -44,7 +44,8 @@ class ObjectChangeSerializer(BaseModelSerializer):
         model = ObjectChange
         fields = [
             'id', 'url', 'display_url', 'display', 'time', 'user', 'user_name', 'request_id', 'action',
-            'changed_object_type', 'changed_object_id', 'changed_object', 'prechange_data', 'postchange_data',
+            'changed_object_type', 'changed_object_id', 'changed_object', 'message', 'prechange_data',
+            'postchange_data',
         ]
 
     @extend_schema_field(serializers.JSONField(allow_null=True))