Prepare CMS API for tech preview

Prepare CMS API for tech preview:

TODO:

• Code:

• • Create CMS scope for access tokens (OK: https://github.com/3scale/porta/pull/3135)
  • Add OpenAPI spec 1 docs to API Docs (OK: https://github.com/3scale/porta/pull/3136)
  • Add "(Tech Preview)" to CMS API section in Active Docs (OK: https://github.com/3scale/porta/pull/3136)
• SaaS Release notes: (amasferr)
  • Andreu will update the 3scale SaaS Release Notes page once this is deployed. (OK: https://access.redhat.com/articles/3107441)
• Anything else? No