Implement customer login

[Ramin-RX7]

• [ ] make a form in forms.py that validates the customer phone number with a regex like the one in user authentication part of the project.
• [ ] Add a template for this form (it is not a complete template, just make the form section and it will be included in other htmls)
• [ ] Connect it to a view/url named customer_login (the action of the form)
• [ ] customer_login must set a session named phone to the user input.
• [ ] then redirect them to the menu url

Note: all of these must be implemented in orders app.