vacuumdb: Move some variables to the vacuumingOptions struct.

vacuumdb: Move some variables to the vacuumingOptions struct.

Presently, the "echo" and "quiet" variables are carted around to
various functions, which is a bit tedious.  To simplify things,
this commit moves them into the vacuumingOptions struct and removes
the related function parameters.  While at it, remove some
redundant initialization code in vacuumdb's main() function.

This is preparatory work for a follow-up commit that will add a
--dry-run option to vacuumdb.

Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CADkLM%3DckHkX7Of5SrK7g0LokPUwJ%3Dkk8JU1GXGF5pZ1eBVr0%3DQ%40mail.gmail.com