For now, the toolbar was hidden from the snippets menu only if:
- it was an image
- it had no editable parent or was outside the wrapwrap
- for model fields that were not html nor views
We also want to hide it for every selected element that is not editable,
as the options will have no effect on such element.
When an element is not editable, it is useless to display the toolbar.
For example, for the website form fields, or the newsletter
subscription, the toolbar was displayed even if it had no effect on the
snippet.
To hide it, we test on the last element at the wysiwyg level.
Part of https://github.com/odoo/odoo/pull/72180
task-2566338
Younn Olivier
3426283c22