Expand Pull Request Links

Why do we need this ?

As a GitHub App developer

I need to:

Add a listener for channels messages and extend pull request links and extend the message with ActionBlock with buttons

So That:

Users can review, merge and comment on PRs right from Rocket.Chat

Acceptance Criteria

• Add Listener for channel messages for GitHub Pull Request links
• Extend messages containing PR link with action blocks so that users to perform actions from the message itself.

Further Comments / References

• Documentation : IModfiyCreater to add Action Blocks
• Documentation : Extending Messages
• Similar Code