Add poetry detector

[tofay]

This detects python dependencies from poetry lockfiles.

New Detector Checklist

• I have gone through the docs for creating a new detector here
• My new detector implements IDefaultOffComponentDetector
• I have created a PR to the verification repo with components that my new detector can find. That's here
• (If necessary) I have updated the Feature Overview table in the README

[github-actions]

👋 Hi! It looks like you modified some files in the Detectors folder.
You may need to bump the detector versions if any of the following scenarios apply:

• The detector detects more or fewer components than before
• The detector generates different parent/child graph relationships than before
• The detector generates different devDependencies values than before

If none of the above scenarios apply, feel free to ignore this comment 🙂

[tevoinea]

This looks awesome!