Display committer avatar and link to committer profile in the last commit info box

Everyone can contribute. Help move this issue forward while earning points, leveling up and collecting rewards.

• Collaborate/take over this issue

Note: This is a follow-up from a typebug: #544803 (closed)

Summary

In !195767 (merged) we ensured both the Author and Committer of a commit are displayed in the last commit info box when the committer and author are not the same.

As a further enhancement, we need to display the committer's avatar and link to their profile if this info is available:

current	proposal

Note, committerAvatarUrl and committerWebUrl (URLs for avatar and their GitLab profile) are not available in the pathLastCommit GraphQL endpoint yet.

We need to add committerAvatarUrl and committerWebUrl to the GraphQL endpoint and ensure we display the avatar and a link to their profile in the UI.