ModID support for SQL data sources

[yodarunamok]

The concept a field to track a record/row's modification is fairly common, and basic support is present in FX.php. That said, support needs to be improved.

[TyrfingMjolnir]

For postgres; its system columns are as follows:
https://www.postgresql.org/docs/current/static/ddl-system-columns.html