Support for Aliases during Trigger Declaration

[tjwrenn]

Feature description
Build support for defining aliases for the "OLD" and "NEW" rows or tables for use in the definition of the triggered action.

Sample Usage
CREATE TRIGGER tr_event_property_type_after_upd
AFTER UPDATE
ON core.event_property_type
REFERENCING OLD TABLE AS deleted_event_property_type
FOR EACH STATEMENT
EXECUTE PROCEDURE core.func_tr_event_property_type_after_upd();

Current Workaround
Use of generic objects:
https://pgmodeler.io/support/docs/329-generic-sql-objects

Additional info
the syntax can be found here:
https://www.postgresql.org/docs/9.1/static/sql-createtrigger.html