Change Test Structure for app/api/dao/task_comment.py

## Description
I want to change the structure of the /tests/task_comments/test_dao.py tests so as to follow the test structure of the rest of the tests in the project.
The link to this file is this:
https://github.com/anitab-org/mentorship-backend/blob/develop/tests/task_comments/test_dao.py

Each method should be tested in a specific class with different methods testing each test case. For example, the file for testing the method delete_comment should be named tests_dao_task_comment_delete_comment.

## Test Cases
The required test cases addressed for this issue are already implemented but should be structured in a different way mentioned in the description.

## Definition of Done
- [ ] All related test cases structured differently should be passing.
- [ ] Approval by 1 mentor.

## Estimation
2 hours