🚀 Feature: Change cookie storage

### 🔖 Feature description

Currently, the cookies are stored in files that can be accessed by other apps.

### 🎤 Pitch

I would suggest that you change the location of the cookies. I would use the plugin flutter_secure_storage for this purpose. I have also implemented this locally for my own projects. If desired, I can provide a corresponding pull request.

### 👀 Have you spent some time to check if this issue has been raised before?

- [x] 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/appwrite/blob/HEAD/CODE_OF_CONDUCT.md)