Find all bills

### Feature 2 : List All Bills
#### User Story:
User can view the Bill List.
#### Prerequisites:
- [ ] Complete Bill Module Feature 1.
- [ ] Implement Bill DAO (Find All)

#### Validations:
##### Business Validation:
- [ ] Check the Bill table is already exists or not.
#### Messages:
- Bill Table Not Found.

#### Flow:

```mermaid
graph TD;

A[Bill Service: Find All Bills] --> B{Business Validation}

B -- Yes --> C[ Bill DAO: Read All Bills]

C --> D[Bill Service: Display Bill Details ]

B -- No --> F[Bill Service: Bill Table Doesn't Exists ]
```