[FEAT] Add Health Check Endpoint

[breezeconcept]

Description

**Closes #443 **

Changes proposed

What were you told to do?

Implement a Health Check Endpoint that allows users to verify if the API is running properly. The endpoint should return a simple response indicating the API's status.

What did you do?

• Added GET / endpoint in HealthCheckController.cs.
• Created a HealthCheckResponse model for standardized API responses.
• Integrated Swagger documentation to improve API visibility.
• Ensured proper response formatting with HTTP status codes.

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Check List (Check all the applicable boxes)

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• My code follows the code style of this project.
• This PR does not contain plagiarized content.
• The title and description of the PR is clear and explains 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 fail neither code linting checks nor unit tests.
• I am only making changes to files I was requested to.

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Screenshots/Videos

✅ Successful Response (200 OK)

{
  "statusCode": 200,
  "message": "Welcome to C-Sharp Backend Endpoint"
}

❌ Error Response (500 Internal Server Error)

{
  "statusCode": 500,
  "message": "Internal Server Error"
}