improvement(create), provide an infra for interactive templates

[davidfirst]

Proposed Changes

• Provide an API for component-templates creator promptOptions. If implemented, bit create will show the prompts, gather the info needed, and then pass this info to the generateFiles() of the template.
• Support adding the prompt-options as flags. (e.g. bit create comp some-template -- --bundler webpack).
• This infrastructure eliminates the need from templates creator to import a prompt library and implement all of it themselves.
• The main reason of implementing this is to enable the IDE extension to display prompts within the IDE UI and create the components according to the user's input.