Changes to Get headers in a specified range of heights

the items/adProofsRoot response's property type changed from no type to string, and format from no format to base16 for status 200

removed the optional property items/$ref from the response with the 200 status

the items/adProofsRoot response's property type changed from string to no type, and format from base16 to no format for status 200

added the optional property items/$ref to the response with the 200 status