add option to the CLI for syncing the stories' data structures with the actual version of their content types' schema

[Slackman2015]

The feature would affect: (check one with "x")

• app.storyblok.com (CMS - Interface)
• api.storyblok.com (CMS - Content Delivery API)
• mapi.storyblok.com (CMS - Management API)
• capi.storyblok.com (Commerce - API)
• Commerce - Interface
• CLI

Is your feature request related to a problem? Please describe.
At the moment it is only possible to add new to the schema added fields to stories of that content type by saving them manually in the UI or by writing a custom script that uses the management API.

Describe the solution you'd like
It would be very helpful to have the possibility to get the actual stories in a space into sync with the actual schema configuration so that this can't cause issues with the implementation of an app when fields aren't present in the JSON.

Additionally an option for cleaning stories up from out of schema fields would also be useful.