Fix code examples for widgets

[stevepiercy]

The documentation seems good, but there are certain things that does not 'work' for widgets / groups.

Example:

    if group.__name__ == 'something':
                    #Not working
                    #group.widgets['due_date'].disabled='disabled'
                    #group.widgets['due_date'].template = Z3ViewPageTemplateFile("my_template.pt")
                    #Works
                    group.widgets['due_date'].mode = interfaces.HIDDEN_MODE

NOTE: all works for default fieldset / 'without group'

                   self.widgets['due_date'].disabled='disabled'
                   self.widgets['due_date'].template = Z3ViewPageTemplateFile("my_template.pt")
                   self.widgets['due_date'].mode = interfaces.HIDDEN_MODE

Originally posted by @espenmn in #1461 (comment)

[petschki]

See my comment here https://community.plone.org/t/disabled-widgets-mode-plone-6-classic/18090/12

This is an issue in current p.a.z3cform==4.3.x for certain widgets but fixed in 4.4.x

[stevepiercy]

@petschki @espenmn can you elaborate here what is the issue, and whether this issue should remain open with a proposed fix, or closed? Thank you!