Code generation changes

[mp-orkes]

Changes in this PR

1. Make code generation interactive.
2. Use the same templates but read available templates from a manifest in the repo.

The format of the manifest is:

 {
    "languages": [
      {
        "name": "Javascript",
        "frameworks": [
          {
            "name": "core",
            "templates": [
              {
                "name": "basic-worker",
                "description": "Basic Javascript worker with Conductor SDK",
                "path": "javascript/worker/core"
              }
            ]
          }
        ]
      }
    ]
  }

NOTES
This repo https://github.com/mp-orkes/cli-templates is just temporary. There will be one under https://github.com/conductor-oss

[mp-orkes]

temporary repo