Add unicode_*_linestyle to \? variables
Add unicode_*_linestyle to \? variables

In a2dabf0 we added the ability to have single or double unicode
linestyle for the border, column, or header.  Unfortunately, the
\? variables output was not updated for these new psql variables.

This corrects that oversight.

Patch by Pavel Stehule.

greenplum-db/gpdb,oberstet/postgres-xl,50wu/gpdb,jmcatamney/gpdb,zeroae/postgres-xl,yazun/postgres-xl,ashwinstar/gpdb,xinzweb/gpdb,pavanvd/postgres-xl,greenplum-db/gpdb,adam8157/gpdb,greenplum-db/gpdb,lisakowen/gpdb,lisakowen/gpdb,Postgres-XL/Postgres-XL,jmcatamney/gpdb,50wu/gpdb,adam8157/gpdb,xinzweb/gpdb,ovr/postgres-xl,zeroae/postgres-xl,yazun/postgres-xl,ashwinstar/gpdb,ovr/postgres-xl,zeroae/postgres-xl,Postgres-XL/Postgres-XL,pavanvd/postgres-xl,jmcatamney/gpdb,50wu/gpdb,ovr/postgres-xl,lisakowen/gpdb,adam8157/gpdb,ashwinstar/gpdb,lisakowen/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,xinzweb/gpdb,yazun/postgres-xl,greenplum-db/gpdb,Postgres-XL/Postgres-XL,ashwinstar/gpdb,pavanvd/postgres-xl,xinzweb/gpdb,oberstet/postgres-xl,greenplum-db/gpdb,adam8157/gpdb,50wu/gpdb,oberstet/postgres-xl,pavanvd/postgres-xl,50wu/gpdb,techdragon/Postgres-XL,xinzweb/gpdb,oberstet/postgres-xl,ovr/postgres-xl,pavanvd/postgres-xl,yazun/postgres-xl,ovr/postgres-xl,adam8157/gpdb,ashwinstar/gpdb,techdragon/Postgres-XL,zeroae/postgres-xl,xinzweb/gpdb,50wu/gpdb,techdragon/Postgres-XL,ashwinstar/gpdb,ashwinstar/gpdb,zeroae/postgres-xl,lisakowen/gpdb,lisakowen/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,xinzweb/gpdb,techdragon/Postgres-XL,xinzweb/gpdb,Postgres-XL/Postgres-XL,lisakowen/gpdb,lisakowen/gpdb,jmcatamney/gpdb,Postgres-XL/Postgres-XL,greenplum-db/gpdb,greenplum-db/gpdb,oberstet/postgres-xl,adam8157/gpdb,50wu/gpdb,yazun/postgres-xl,greenplum-db/gpdb,adam8157/gpdb,adam8157/gpdb,techdragon/Postgres-XL,jmcatamney/gpdb,50wu/gpdb