Add the allow_new setting also for the simple widget

tnx

Automatically closed - issue fixed for 2 weeks with no activity.

Bulk reopen.

This will also need to update config/schema/inline_entity_form.schema.yml to add this as a possible setting for the simple widget.

Yah. Fortunately properly configured tests catch that. If they don't, open an issue to make them.

Hah, whoops, except that file already has bogus definitions for this and a couple other settings that currently only live in the complex widget. 😅