As multiple configurations are possible, we need to be able to edit them.
Add a "Form configurations" section
Display all field configurations in a list, starting the "Default configuration"
Add an "Add new" link in the "Form configurations" section
Click on a configuration / Add new will open the new / edit page for a form configuration
Note: drag/drop is in INTEGRATED-257, read-only is currently not in scope and is a future feature
When the selected configuration is not the default, a field "Name" will be added to enter the name of the configuration
When the selected configuration is not the default, the "Name" is a required field
Then opening the form will be generated showing:
First the fields which have been configured before, ordered by configured order, excluding the fields which have been removed from the content type configuration
Second the fields which have been added to the the content type configuration and are not configured yet.
Note: the "Readonly" checkbox is currently out of scope
Adding custom fields is also in this issue
Click Save will save the form configuration
Add content type, define multiple field configurations, save it
Open the content type again and verify if the configurations are saved
Edit the content type and verify the changed have been saved
Verify the name field for non-default configurations only