Missing program_XXX calling in pgbench tests

Dear hackers,

While reviewing another thread I found #SUBJECT.

Most of client program executes program_help_ok, program_version_ok,
program_options_handling_ok() in their test, but pgbench does not do. Instead
pgbench has own tests for --help and --version options.

One concern is that program_help_ok() checks whether lines are too long or not.
For now, the rule seems to be kept but not sure in future.

I feel that we can replace tests with common function, like attached. How do you
think?

Best regards,
Hayato Kuroda
FUJITSU LIMITED