Github Review with PR Comments

[dbpolito]

This adds support for Github Integration to add PR Review Comments instead of only adding review as a normal comment.

1. This introduces a new local tool github_pr_comment, which is only available within opencode github run
2. This supports single / multi line review comments with suggestions

To Be Determined

This still adds a final pr review comment with general message, maybe we should improve the prompt to only add a comment if the PR review comments aren't enough context so we don't always comment? Or make another tool to add comment, not sure.

I kept the PR simple to we can expand later on.

[rekram1-node]

/review