Create user

### Feature: Create User
>Create a new user in a database.
#### Pre-requisites:
- [ ] user DAO( create user )
- [ ] user service ( create(User user) )
#### Validations:
- [ ] Form Validation
* create( User user )
* user null
* name ( null, empty, pattern )
* email ( null, empty, pattern )
* password ( null, empty, pattern )
* phone number ( length, >= 600000001 && <= 9999999999 )
- [ ] Business Validation
* Email Already exists
#### Messages:
* Invalid User object
* Invalid name input
* Invalid email input
* Invalid password input
* Invalid phone number input
* User already exists
#### Flow:
```mermaid
graph TD;

A[Value Passed to UserService - User Object] --> B[Form Validation & Business Validation]

B--> C{Validation Result}

C -- Valid --> D[Value Passed to UserDAO]

D --> E[Store Value in Database]

C -- Invalid --> F[Validation Exception]
```

从 UserService create(User user) 入口点开始，跟踪表单和业务验证流程，直到 UserDAO 和数据库。将列出的验证规则和消息作为验收标准，包括拒绝重复的电子邮件地址和无效的用户字段。

由索引模型根据 Issue 内容生成。