Support OpenAPI specs with multiple flows in oauth2 sec scheme

      ---
      openapi: "3.0.0"
      info:
        title: "some title"
        version: "1.0.0"
      paths:
        /pet:
          get:
            operationId: "getPet"
            responses:
              200:
                description: "successful operation"
      security:
        - petstore_oauth:
          - write:pets
          - read:pets
      components:
        securitySchemes:
          petstore_oauth:
            type: oauth2
            flows:
              clientCredentials:
                tokenUrl: http://example.org/api/oauth/dialog
                scopes:
                  write:pets: modify pets in your account
                  read:pets: read your pets
              authorizationCode:
                authorizationUrl: https://example.com/api/oauth/dialog
                tokenUrl: http://example.org/api/oauth/token
                scopes:
                  write:pets: modify pets in your account
              implicit:
                authorizationUrl: http://example.org/api/oauth/dialog
                scopes:
                  write:pets: modify pets in your account
              password:
                tokenUrl: http://example.org/api/oauth/dialog
                scopes:
                  write:pets: modify pets in your account
                  read:pets: read your pets
                  read:pets: read your pets