When cloning a website_form field, we rerender the cloned field to
reassign its elements ids and for attributes with a unique ID instead of
the old ones.
Rerendering the list also removes an issue with Selection fields that
were not visible after a clone and a save, as it was usually done after
a _rerenderXML, not executed after a clone.
Also, _renderField docstring was wrong, and its return values
terminology have been replaced with correct one.
task-2485093
X-original-commit: 92bacc8907fa9577805b28a11894e7a006b2a5bf
Part-of: odoo/odoo#75908
Guillaume (gdi)
151d570933