Iterate with PR comments

[irgolic]

Functionality to iteratively amend PRs; currently it regenerates the PR every time you run it on an issue, I'd like it to respond code review/pull request comments, adding new commits and a new comment.

Draft for this is PR #28.

TODO is:

• rail_v1 is missing an amendment implementation (but all the models are there) 
https://github.com/irgolic/AutoPR/pull/28/files#diff-4318038294852a7dbaf7f9e132470168fea537d7593c95755296b0b467228edcR162
• event service needs to correctly interpret the github event for these two new events https://github.com/irgolic/AutoPR/pull/28/files#diff-8d5dc9a95027cb9ebfb8a5c88201744a8e02367997013b710a71a4a7fe321cffR25
• workflow file (in whichever repo you're testing with) needs to pass along code review comments too
https://github.com/irgolic/AutoPR/blob/main/.github/workflows/create-pr-from-issue.yml#L4
• comment trigger needs to handle PR comments and code review correctly (maybe don't need to use 🚀 emoji for code review submissions to trigger?)
https://github.com/irgolic/pull-request-comment-trigger/blob/master/index.js
• generation service needs to handle the two new event types https://github.com/irgolic/AutoPR/blob/main/autopr/services/generation_service.py#L46

[irgolic]

Accidentally triggered it with the rocket emoji (this was back before AutoPR was triggered by labels)

It failed because Github Action tokens can't edit workflows, I'd need to replace it with a personal access token. It also can't pull the branch of #28 – when this issue is solved, we will be able to iterate on PRs in the PR comments section itself. But cute effort honestly, it created correct little stubs ready to be filled out.

[irgolic]

Closed by #28, code review split off into #109