pgbench: Remove \cset
Partial revert of commit
6260cc550b0e, "pgbench: add \cset and \gset
commands".
While \gset is widely considered a useful and necessary tool for user-
defined benchmarks, \cset does not have as much value, and its
implementation was considered "not to be up to project standards"
(though I, Álvaro, can't quite understand exactly how). Therefore,
remove \cset.
Author: Fabien Coelho
Discussion: https://postgr.es/m/alpine.DEB.2.21.
1903230716030.18811@lancre
Discussion: https://postgr.es/m/
201901101900.mv7zduch6sad@alvherre.pgsql
projects / postgresql / commit