Refactor: Signup Form

[sonylomo]

Description

• The current sign-up form limits users to selecting from pre-existing business categories. We want to give users the option to add a new category.
• The signup form currently does not validate the phone number.
• The city input accepts any value.
• The MapURL doesn't validate google urls

Task

• [x] Allow the user to add a custom category when no existing options are available.
• [x] Implement phone number validation using Phonelib and Zod.
• [x] Convert the city input to a select input with a list of cities.
• [x] Use regex to validate mapURL

[Soft-Craft-Tech]

I hope this is fixed.