Changes to List Webhooks

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

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

query request parameter cursor list-of-types was widened by adding types null

for the query request parameter cursor, the type was generalized from string to no type

added the non-success response with the status 401

added the non-success response with the status 403

added the non-success response with the status 429

endpoint added