Users are not supposed to be able to change the field type for fields
that are required by the model. This commit removes the option to change
the field type for fields required by the model.
Steps to reproduce the bug fixed by this commit:
- Put a form on the page of a website
- Set the form action to "Send an E-mail".
- Click on the "Your Email" field
=> The user can change the type for this field. We don't want this
because this field is linked to the `email_from` field in the
`mail.mail` model. This commit fixes this issues for every model
required fields.
task-3302433
Part-of: odoo/odoo#120874
Guillaume (gdi)
cd7a7237b1