Bot should create a comment and then update it

[larryhudson]

Currently, when the user creates an issue, the bot will respond with an 'eyes' reaction, and then create a comment when it is finished handling.

I think it would be more clear if instead, we created a comment when the webhook is first received, and then update that comment when we complete the task.

So instead of doing the 'eyes' react, then handling the comment, then changing to a 'rocket' react, I think we should:

• create a comment and say that the task has been added to the queue. Save the comment ID so that it can be edited later.
• when the task commences, update the comment and say that it is now working on the task.
• when the completes, update the comment again the final result.
• still respond with a 'rocket' reaction to say that the task is completed.

@Aiderbot could you have a look at this?

[larryhudson-aider-github[bot]]

I've created a pull request to address this issue: https://github.com/larryhudson/aiderbot/pull/70

Time taken to create this PR: 100.32 seconds