Changes to List marketplaces

added the optional property message to the response with the 400 status

the endpoint scheme security bearerAuth was added to the API

the endpoint scheme security denApiKey was added to the API

added the required property items/items/externalKey to the response with the 200 status

added the optional property capability to the response with the 400 status

the items/items/createdByOrgMembershipId response's property pattern ^om_.* was removed for the status 200

the items/items/id response's property pattern ^mkt_.* was removed for the status 200

the items/items/organizationId response's property pattern ^org_.* was removed for the status 200