Add security descriptors to OpenAPI specifications.

[jhernand]

Add security descriptions to the OpenAPI specifications, for example:

/api/fulfillment/v1/cluster_orders:
  post:
    operationId: ClusterOrders_Place
    security:
      - openIdConnect:
        - openid
        - profile

And a security component:

components:
  securitySchemes:
    openIdConnect:
      type: openIdConnect
      openIdConnectUrl: https://.../.well-known/openid-configuration

[jhernand]

Thanks @computate, and feel free to elaborate.