AFAICT this is a libpq functionality, and since the JDBC driver is not libpq based then it can't use that functionality.
And it doesn't looks to be that useful for JDBC users:
postgres=# select * from pg_catalog.pg_type; postgres=# \errverbose There is no previous error. postgres=# select * from pg_catalog.pg_types; ERROR: relation "pg_catalog.pg_types" does not exist LÍNEA 1: select * from pg_catalog.pg_types; ^ postgres=# \errverbose ERROR: 42P01: relation "pg_catalog.pg_types" does not exist LÍNEA 1: select * from pg_catalog.pg_types; ^ UBICACIÓN: parserOpenTable, parse_relation.c:1138 postgres=# select 1/0; ERROR: division by zero postgres=# \errverbose ERROR: 22012: division by zero UBICACIÓN: int4div, int.c:719