Show all review comments together in a thread under the main review message.

[BURG3R5]

Multiple messages for a single review is annoying.

[BURG3R5]

Two possible ways of doing this:

1. Store incoming pull_request_review_comment events till the next pull_request_review event.
2. Disregard incoming pull_request_review_comment events. Whenever a pull_request_review.changes_requested event is thrown, hit the comments endpoint to fetch all associated comments right then.

PS: PR comments other than review comments also need to be handled.

[BURG3R5]

Further research in the two methods gave the following insight:

1. In the first method, we can match json['comment']['pull_request_review_id'] to json['review']['id'] to confirm the ownership. This will not require any token, but will require storage.
2. In the second method, sending a GET request to the review event's json['pull_request']['review_comments_url'] will give list of comments associated with that review. This will not require any storage, but will require a OAuth token, probably with read access to the org.

PS: Extracting the "PR comments other than review comments" thing to another issue.