Course Module | Delete Feature

# Course Delete Process

### User Story:

- When a user provides a valid courseID and requests to delete the course, the system successfully removes the course from the system and responds with a message confirming the successful deletion.
- When a user provides an invalid courseID and attempts to delete the course, the system responds with an "Invalid" message, indicating that the course was not successfully deleted.

### Task

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

### DAO
- deleteCourse()

### Service
- removeCourse()

### Service Test
TestDeleteCourseFeature
- testDeleteCourseSuccess()
- testDeleteCourseFailure()

### Estimation
- 1 hour

# Flowchart
```mermaid
flowchart TD
A[Start]
B[User Requests to Delete Course]
C[Validate CourseID]
D{Validation Successful?}
E[Retrieve Course for Deletion]
F[Display Course Deletion Confirmation]
G[User Confirms Deletion]
H{Deletion Confirmed?}
I[Delete Course Data]
J[Course Deletion Successful]
K[Display Validation Error]
L[Display Deletion Error]
M[End]

A --> B
B --> C
C --> D
D -- Yes --> E
E --> F
F --> G
G --> H
H -- Yes --> I
I --> J
H -- No --> M
D -- No --> K
K --> F
I --> L
L --> M
J --> M

```