Direct users to leave a 👍/👎 down on Duo Code Review comments

Problem to Solve

We need to provide users with additional feedback and interaction instructions for each comment that Duo Code Review leaves. This will allow us to better surface what's working or isn't working well with the reviews.

Proposal

We should help guide users to leave feedback and interact:

1. Add a new string to the bottom of each comment: Rate this response • `@GitLabDuo` in reply for more questions
2. Add placeholder emoji reactions of 👍 and 👎 to each comment by default, with a count of 0, so that it's easier for users to interact.

This should only be done on the review comments and not:

1. Follow up interaction comments
2. The initial summary review comment

Note: Design image differs because it is not possible to display emoji reactions without a number #521724 (comment 2388835408).

First draft

If it's possible to do this in a slightly different style or smaller font that may help so that it doesn't distract or overwhelm the normal review feedback: