Changes to Get Custom Metrics

added the new optional query request parameter source

added the optional property data/items/source to the response with the 200 status

added the optional property metrics/items/source to the response with the 200 status

added the new optional header request parameter X-Organization-Id

added the optional property data/items/created_by to the response with the 200 status

added the optional property data/items/updated_at to the response with the 200 status

added the optional property data/items/updated_by to the response with the 200 status

added the optional property metrics/items/created_by to the response with the 200 status

added the optional property metrics/items/updated_at to the response with the 200 status

added the optional property metrics/items/updated_by to the response with the 200 status

endpoint added