Design module | Create Design Feature

## Creating Design Process

### User Story
- As a user, I want to be able to create a new design and add it to the collection.
- If a design is without valid details, the system should display an error message.

### Task: Implement Design Creation
- [ ] Develop the Data Access Object (DAO) Layer for design creation.
- [ ] Implement the Service Layer to handle the design creation process.
- [ ] Create JUnit Test Cases to validate the correctness of the design creation functionality.
- [ ] Ensure that all test cases pass successfully.
- [ ] Enhance code clarity by adding clear and concise comments to explain intricate logic.

### DAO:
- [ ] createDesign()

### Service:
- [ ] createDesign()

### Test:
- [ ] testCreateDesignSuccess()
- [ ] testNegativePriceValue()
- [ ] testNegativeRooms()
- [ ] testNullDesignObject()

### Estimation
- [ ] 4 hrs

## Flow
``` mermaid
graph TD
A[[Start]] -->|Architect Initiates Design Creation| B[Validate Design]
B -->|Valid| C[Search Existing Designs]
B -->|Invalid| E{Validation Exception}
C -->|Success| I[Design Added Successfully]
E -->|Fail| G[Failed to Add Design]
G --> H[[End]]
I --> H
```