feat(comments): added Get Article comments API

[mubbi]

This pull request introduces a new feature to retrieve paginated comments for articles, including one level of child comments. It adds a new controller, request validation, resource classes, and database seeding for testing, as well as updates the model and service layer. Comprehensive test coverage is also included.

New Feature: Retrieve Paginated Comments

Controller and API Endpoint

• Added GetCommentsController to handle requests for fetching comments with pagination and child comments. It includes error handling and response formatting.
• Added a new API route to fetch comments for a specific article: /articles/{article:slug}/comments.

Request Validation and Resource Formatting

• Introduced GetCommentsRequest for validating query parameters such as per_page, page, and parent_id.
• Created CommentResource to structure the JSON response for comments, including user details, content, and replies.

Backend Enhancements

Model Updates

• Updated the Comment model to include replies_count and replies_page properties, and added a replies relationship to fetch child comments. [1] [2]

Service Layer

• Added getArticleComments method in ArticleService to fetch paginated comments with user details, reply counts, and limited child comments.

Testing and Seeding

Database Seeder

• Added ArticleCommentSeeder to generate test data for articles, comments, and nested comments.

Feature Tests

• Implemented tests for GetCommentsController to verify functionality, including successful responses, empty results, and error handling.