🚀 Feature: Add option to customise Phone Auth OTP

### 🔖 Feature description Ability to customise phone auth otp message. Currently it only sends the otp. If not customisable due to registered template constraint atleast if we the message stated Your OTP for `app_name` is `otp`, it would be really helpful ### 🎤 Pitch This feature is trivial to any production grade software as it results in bad UX when users are unable to grasp why he/she received an integer text. ### 👀 Have you spent some time to check if this issue has been raised before? - [ ] I checked and didn't find similar issue ### 🏢 Have you read the Code of Conduct? - [X] I have read the [Code of Conduct](https://github.com/appwrite/.github/blob/main/CODE_OF_CONDUCT.md) PS: I found a similar issue for this, but it mentioned being able to change sms provider but for cloud I didn't find that. It also mentioned creating env variables for templates, so as I couldn't find the option to create env in appwrite cloud I created a separate issue