Content Release Notes for 2.1.0

Introduced CustomContentFields, enabling the creation of custom fields in the admin application. This feature is useful when a content item requires a field that is not part of the standard ContentFields metadata type. These custom fields allow users to define a list of Enums or values that can be selected from an external API.

This version includes all changes up to 2.0.6 Release Notes.

Fixed SQL changeset failing because column count is not correct for the current version of the ContentModel domain.