Implement Get mentor by id endpoint (Public endpoint)

[Madhawa97]

Purpose

The purpose of this PR is to fix #15

Goals

This issue involves implementing an API to get mentors by id. The endpoint should allow clients to make a GET request to {{baseUrl}}/api/mentors/{{mentorId}}.

{
    "mentorId": 5,
    "category": "Computer Science",
    "profile": {
        "contact_email": "mandy@gmail.com",
        "first_name": "Mandy",
        "last_name": "Fernando",
        "image_url": "https://www.linkedin.com/mandy",
        "linkedin_url": "https://www.linkedin.com/mandy"
    },
    "mentees": []
}

Approach

• Create a controller for the /controllers/mentor endpoint in the backend (create the route mentor if not created).
• Implement appropriate error handling and response status codes for different scenarios (e.g., validation errors, database errors).
• Write unit tests to validate the functionality and correctness of the endpoint.

Checklist

• [x] This PR doesn't commit any keys, passwords, tokens, usernames, or other secrets.
• [x] I have read and understood the development best practices guidelines ( http://bit.ly/sef-best-practices )
• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation

Related PRs

Test environment

macOS 13 latest, local Postgres 15 env.

[Madhawa97]

Please verify if the request URL is {{baseUrl}}/api/mentors/{{mentorId}}. Currently, I've used that. It has given as {{baseUrl}}/api/mentees/mentors/{{mentorId}} in the API documentation. cc: @anjula-sack @janithlahirukariyawasam

[anjula-sack]

Please verify if the request URL is {{baseUrl}}/api/mentors/{{mentorId}}. Currently, I've used that. It has given as {{baseUrl}}/api/mentees/mentors/{{mentorId}} in the API documentation. cc: @anjula-sack @janithlahirukariyawasam

Sorry, my bad. I updated the doc. It's {{baseUrl}}/api/mentors/{{mentorId}}

[Madhawa97]

Thank you @anjula-sack.

[Madhawa97]

Fixed merge conflicts with #9.