Comment Module | Create Feature

# Comment Create Process

### User Flow:

- When a user (buyer) adds a new comment to the course with valid details, they will receive a message confirming the successful addition of the comment.
- , if the user (buyer) attempts to add a new comment to the course with invalid details, or if the provided courseID or userID is invalid, they will receive a message stating that the comment details could not be found.

### 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
- createComment()

### Service
- registerComment()

### Test
TestCreateCommentFeature
- testCreateCommentSuccess()
- testCreateCommentFailure()

# Flowchart
```mermaid
flowchart TD
A[Start]
B[User Requests to Create Comment]
C[Validate Comment Details]
D{Validation Successful?}
E[Save Comment Data]
F[Comment Creation Successful]
G[Display Validation Error]
H[End]

A --> B
B --> C
C --> D
D -- Yes --> E
E --> F
D -- No --> G
G --> H
F --> H

```