The Codec interface is now implemented by *pgtype.JSONCodec
and *pgtype.JSONBCodec instead of pgtype.JSONCodec and
pgtype.JSONBCodec, respectively. This is technically a breaking
change, but it is extremely unlikely that anyone is depending on this,
and if there is downstream breakage it is trivial to fix.
Fixes#2005.
- Remove rarely used ScanPlan.Scan arguments
- Plus other refactorings and fixes that fell out of this change.
- Plus rows Scan now handles checking for changed type.