Design module | List Design Feature

## List Design Process

### User Story
As an architect, I want the ability to view a list of all the designed items in the collection. The system should provide me with a list that includes details such as design names, IDs, URLs, prices, and the number of rooms. This way, I can easily monitor and manage the designs that are part of the collection.

### Task: Implement Design Listing for Architects
- [ ] Develop the Data Access Object (DAO) Layer for listing designs.
- [ ] Implement the Service Layer to handle the design listing process for architects.
- [ ] Create JUnit Test Cases to ensure the correctness of the design listing functionality.
- [ ] Verify that all test cases are passing successfully.
- [ ] Enhance code clarity by adding clear and concise comments to explain intricate logic.

### DAO:
- [ ] listDesigns()

### Service:
- [ ] listDesigns()

### Test:
- [ ] testListDesignSuccess()
- [ ] testListDesignFailure()

### Estimation
- [ ] 2 hrs

## Flow
``` mermaid
graph TD
A[[Start]] -->|Architect Initiates Design Listing| B([Fetch Designs])
B -->|Designs Found| C([Display Design List])
B -->|No Designs Found| D{{No Designs Available}}
C --> H[[End]]
D --> H
```