[FEAT] Fetch All Subscribers to Newsletter (Paginated)

[Qazim-tec]

🚀 [FEAT] Fetch All Subscribers to Newsletter (Paginated)

📝 Description

Closes #411

This PR implements an endpoint to retrieve all active newsletter subscribers. The endpoint supports pagination, allowing clients to specify the page number and limit per request.

---

✅ Changes Proposed

• Added GET /api/v1/pages/newsletter/subscribers endpoint.
• Implemented pagination with configurable page size.
• Ensured proper response formatting and status codes.
• Added unit tests for pagination and response validation.

---

📌 Requirements

Endpoint Details:

• Method: GET
• URL: /api/v1/pages/newsletter/subscribers
• Headers:
  • Content-Type: application/json

Query Parameters

Parameter	Type	Required	Default	Description
page	Integer	❌ No	1	The page number to retrieve.
limit	Integer	❌ No	10	The number of subscribers per page.

---

✅ Check List

• My code follows the code style of this project.
• This PR does not contain plagiarized content.
• The title and description of the PR are clear and explain the approach.
• I am making a pull request against the dev branch (left side).
• My commit messages follow the requested structure.
• My code additions will not fail linting checks or unit tests.
• I am only making changes to files I was requested to modify.

🔹 Responses

✅ Successful Response (Status 200)

❌ Error Response (No Subscribers Found)

❌ Error Response (Invalid Pagination Parameters)

🧪 Unit Tests