pgsql: Report index vacuum progress.

Report index vacuum progress.

This commit adds two columns: indexes_total and indexes_processed, to
pg_stat_progress_vacuum system view to show the index vacuum
progress. These numbers are reported in the "vacuuming indexes" and
"cleaning up indexes" phases.

This uses the new parallel message type for progress reporting added
by be06506e7.

Bump catversion because this changes the definition of
pg_stat_progress_vacuum.

Author: Sami Imseih
Reviewed by: Masahiko Sawada, Michael Paquier, Nathan Bossart, Andres Freund
Discussion: https://www.postgresql.org/message-id/flat/5478DFCD-2333-401A-B2F0-0D186AB09228(at)amazon(dot)com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/46ebdfe164c61fbac961d1eb7f40e9a684289ae6

Modified Files
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doc/src/sgml/monitoring.sgml | 23 ++++++++++++
src/backend/access/heap/vacuumlazy.c | 70 ++++++++++++++++++++++++++++++-----
src/backend/catalog/system_views.sql | 3 +-
src/backend/commands/vacuumparallel.c | 9 ++++-
src/include/catalog/catversion.h | 2 +-
src/include/commands/progress.h | 2 +
src/test/regress/expected/rules.out | 4 +-
7 files changed, 100 insertions(+), 13 deletions(-)