Strapi: Template submission endpoint

[boazpoolman]

When ever a community developer wants to submit their template to the marketplace, they will have to fill in a form and ultimately call the template submission endpoint in Strapi. The endpoint has a couple requirements:

1. It has to be an authenticated endpoint that is called with an API token
2. The endpoint has to be proxied through the Next.js server side layer, preventing the API token from being leaked to the client
3. Templates can only be created through this custom endpoint and not by using the default CREATE endpoint of the template CT
4. The endpoint should either create a UP user + profile, or recognize the email address and add the new package to that user
5. It should setup all the necessary relations required to bootstrap a new template