pgsql: psql: Fix tab completion for FOREIGN DATA WRAPPER and SUBSCRIPTI

psql: Fix tab completion for FOREIGN DATA WRAPPER and SUBSCRIPTION.

Commit 8185bb5347 extended the CREATE/ALTER SUBSCRIPTION and
CREATE/ALTER FOREIGN DATA WRAPPER commands, but missed the
corresponding tab-completion logic. This commit fixes that oversight
by adding completion support for:

- The CONNECTION keyword in CREATE/ALTER FOREIGN DATA WRAPPER.
- The list of foreign servers in CREATE/ALTER SUBSCRIPTION.

Author: Yamaguchi Atsuo <acrobatcoder@gmail.com>
Discussion: https://postgr.es/m/CAKSyusJWdWcUKVd3qJXcEaQxJewGymQWV_r3-mc=Knrqo0AZ_g@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/5fa7837d9a3970c5ea372bb90b916b54478fb818

Modified Files
--------------
src/bin/psql/tab-complete.in.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)