Book Module | Delete Book Feature

# Creating Book Process

### User Story
As a librarian, I need to be able to remove books from the library's collection. When I identify a book that needs to be removed, I want to initiate the deletion process. If the book I intend to delete is not found, the system should provide a message indicating that the book is not available for deletion.

### Task

- [x] Implement Data Access Object (DAO) Layer.
- [x] Implement Service Layer.
- [x] Create JUnit Test Cases.
- [x] Ensure that the tests cases are passing.
- [x] Write clear and concise comments in the code to explain complex logic.

#### DAO
- deleteBook()

#### Service
- deleteBook()

#### Junit Test
- testValidDeleteBook()
- testInvalidDeleteBook()

### Estimation
- 3 hours

# Flowchart

```mermaid
graph TD
A[[Start]] --> B(Librarian Initiates Delete Book)
B --> C[(Search Book to Delete)]
C --> |Book Not Found| D{{Service Exception}}
D --> |Fail| E([Failed to Delete Book])
C --> |Book Found| G([Confirm Deletion])
G --> |Delete Book Record| F([Book Deleted Successfully])
E --> |Returns False|I[[End]]
F --> |Returns True|I

style F fill:#dfd,stroke:#333
style E fill:#fdd,stroke:#333