Create User

### Feature: Create User

>Create a new user in a database.
#### Pre-requisites:
- [ ] user table
- [ ] user model
- [ ] user DAO( create )
- [ ] user service ( create )
#### Validations:
- [ ] Form Validation
* user null
* name ( null, empty, pattern )
* email ( null, empty, pattern )
* password ( null, empty, pattern )
* phone number ( length, >= 600000001 && <= 9999999999 )
- [ ] Business Validation
* Check whether the email is already exists
#### Messages:
* Invalid User object
* Name cannot be null or empty
* Password format is invalid.
* Invalid phone number
* The email already exists
#### Flow:
```mermaid
graph TD;
A(Argument Passed to UserService - User Object) --> B(Form Validation)
B--Valid--> C(Business Validation)
B--Invalid-->I(Throw Validation Exception)
C -- Valid --> E(Argument Passed to UserDAO)
E --> F(Store Value in Database)
C -- Invalid --> H(Throw Validation Exception)
```

The issue specifies a User model, User DAO, User service, user table, and create flow, but names no files or tests. Start by locating the existing model, service, DAO, and database structure, then trace how validation and persistence are organized. Done means user creation, listed form and business validations, and the specified messages are covered.

Written by the indexing model from the issue text.