Show relevant reviews from the chrome extension for individual users

[avikalpg]

If the "PR COMMENT" feature flag for a repository is turned off, then the Chrome extension should show the list of relevant reviewers with their relative relevance.

Purpose: Individual users should also know the relevant reviewers for their own pull requests so they can directly ping them to review their pull requests.

Design:
Create a section in the GitHub/Bitbucket UI right below the title of the pull request that looks like this:

Optionally, we can also add check marks next to the reviewers who have reviewed the pull request (even if GitHub/Bitbucket says that their review has been dismissed, we can maintain the right approval information on this element.)

[avikalpg]

A cleaner representation of the design.