Revive num_dead_tuples column of pg_stat_progress_vacuum

Hi,

Commit 667e65aac3 changed num_dead_tuples and max_dead_tuples columns
to dead_tuple_bytes and max_dead_tuple_bytes columns, respectively.
But at PGConf.dev, I got feedback from multiple people that
num_dead_tuples information still can provide meaning insights for
users to understand the vacuum progress. One use case is to compare
num_dead_tuples to pg_stat_all_tables.n_dead_tup column.

I've attached the patch to revive num_dead_tuples column back to the
pg_stat_progress_vacuum view. This requires to bump catalog version.
We're post-beta1 but it should be okay as it's only for PG17.

Feedback is very welcome.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com