Modify SPARQL query for cleaved proteins

[nataled]

Currently the query just looks for 'cleaved' but should instead look for any subclass of PR:000018264 "proteolytic cleavage product".

TBD: should these include InitMet- or SigPep- cases? Technically these should be included as 18624 is defined as an intersection between protein and GO:0016485 "protein processing", which does include these. However, we typically use parthood (or lack thereof) to indicate those cleavage types and thus won't be included in the results.