Add tool for managing projects

Initial concept: tool should support package API that can be used by both a CLI and Cloud Code for enhancing developer experience working with Functions Framework for Dart projects, making it easy to create, deploy, and monitor function apps.

- [ ] Including project scaffolding support; generate example and starter projects (relates to #19 - one or more starter project templates can also be exposed through stagehand)
- [ ] Minimize need for installing other tools (gcloud, stagehand, etc) to work with cloud projects
- [ ] Associate current project with a Google Cloud project, deploy, get URL, open logs/traces directly
- [ ] Potentially be able to add new handlers (and tests) for different HTTP methods and Cloud Event types to an existing project.