Refactored project

[hrshdhgd]

• [x] ~kgcl_schema~ dir -> kgcl
• [x] Add target slot to SynonymPredicateChange
  • Design change reasoning: In this particular class, since the "action" is predicate change, I propose old_value and new_value to be the actual predicate value that relates to the synonym of the node. The synonym itself could be in the target slot?
• [x] Add predicate slot to NewSynonym