Update category

### User story :

Category deatils are successfully updated and stored in databse.

### Pre-requisites:- [ ] category DAO(update category)

- [ ] complete feature 4 - create category
- [ ] category dao ( create )
- [ ] category service ( create )

#### Validations:

- [ ] Form Validation
* id (less than 0)
* name ( null, empty, pattern )

- [ ] Business Validation
* Check whether the id exist

#### Messages:
* Id cannot be 0 or in negative
* Name cannot be null or empty
* Name should be match with the given pattern
* Category id does not exists

#### Flow:
> Invalid When a category's name is not in use or when the input provided does not meet the criteria, categories arise.

```mermaid
graph TD;

A(CategoryService - int id, String name) --> B(Form Validation) -- Valid --> C(Business Validation)
B -- Invalid --> G(Validation Exception)
C -- Valid --> D(Argument Passed to CategoryDAO)
D --> E(Store Value in Database)
C -- Invalid --> F(Validation Exception)
```