Enhance Development Experience for Phone Authentication

The current phone authentication feature in Supabase works effectively in production environments. However, it can be challenging to utilize during the development phase. To improve the development experience, I suggest implementing the following enhancements: 1. Test Phone Number Support: Currently, there is no provision to add a test phone number for development purposes. It would greatly benefit developers if Supabase allowed the usage of predefined test phone numbers. For example, being able to utilize a number like "+33 6 12 34 56 78" and expect a predictable OTP, such as "123546". This feature would be particularly valuable during app testing phases and when providing access to testers. 2. Local Development Setup: It is currently impossible to set up phone authentication locally. This limitation hampers the ability to develop and test phone authentication functionality in local development environments. Having the ability to configure and test phone a…