Changes to Insert dataset rows

added the new optional request property rows/items/custom

request property rows/items/expectedOutput list-of-types was widened by adding types array to media type application/json

request property rows/items/input list-of-types was widened by adding types array to media type application/json

request property rows/items/metadata list-of-types was widened by adding types array to media type application/json

request property rows/items/output list-of-types was widened by adding types array to media type application/json

added the new optional request property rows/items/expectedOutput

endpoint added