Display pending label for all pending comments on the description page

[RMacfarlane]

Comments that are pending should be marked with a label like they are on GitHub. In this example, I replied twice to an existing comment. Both "test" comments have not yet been posted, but look like they are already appended to the existing review.

[akosasante]

👋 I'd like to take a look at resolving this

[RMacfarlane]

@akosasante Great! The code that renders the comments is here:

vscode-pull-request-github/preview-src/comment.tsx

Line 20 in 1432e8a

export function CommentView(comment: Props) {