#162497653 Implements api to update intervention comment

[valenstical]

What does this PR do? This PR sets up endpoint to update the comment of a specific intervention record

Description of tasks

• Implement unit test for the endpoint
• Setup API endpoint for PATCH /api/v1/interventions//comment and make sure all tests are passing

How can this PR be tested

• Using Postman, set the request method to PATCH
• Make requests to https://ireporter-nigeria.herokuapp.com/api/v1/interventions//comment

What are the relevant pivotal tracker stories? #162497653

Screenshot N/A