Get an item by project counter or occurrence UUID. Either uuid or counter must be provided.
uuid must be an ocurrence UUID for an occurrence in the item. Occurrence UUIDs are part of the response in https://docs.rollbar.com/reference/create-item.
counter must be an item counter for an item in the project. The counter can be found in URLs like https://rollbar.com/myaccount/myproject/items/456/ (456 is the counter).