[REV] website: allow multiple fields with same label in a form

This reverts [this commit]. Indeed, [this commit] was too restrictive on
the visibility dependencies and blocked the creation of some conditions.

Example:
- Add a form on the website.
- Add two fields and rename them (by "test" for example).
- Change the visibility of the first one and set it to "Visible only if
Your Name is equal to Boule"
- Change the visibility of the second one and set it to "Visible only if
Your Name is equal to Bill"

-> The field "test" will be visible if "Your name" is "Boule" or "Bill".

[this commit]: https://github.com/odoo/odoo/commit/17c93a4ca14119c5bf94270546adaf86a4378d67



closes odoo/odoo#133709

Signed-off-by: Arthur Detroux (ard) <ard@odoo.com>