PAC: Align UX for create repo CLI commands

Goal

User requires to learn and use different CLI commands for adding a Git repo to the cluster depending on admin has configured a GitHub App or if webhooks should be used. From the user's perspective, all these flows are to achieve the same outcome which is adding a Git repo to the cluster. Therefore the goal is to unify the CLI follows behind a single command.

Acceptance Criteria

• pac create repo is the only command user needs to run in order to add a repository to the cluster with GitHub Apps as well as GitHub, GitLab and BitBucket webhooks
• pac setup nnn-webhook only sets up webhooks for existing repositories

Questions

• How should user specify the git provider in create repo command?
  • Flags like `--gitlab-webhook`
  • Choose from drop down [GitHub Apps, GitHub Webhook, GitLab, BitBucket]
  • ?