pgsql: Add mode and started_by columns to pg_stat_progress_vacuum view.

Add mode and started_by columns to pg_stat_progress_vacuum view.

The new columns, mode and started_by, indicate the vacuum
mode ('normal', 'aggressive', or 'failsafe') and the initiator of the
vacuum ('manual', 'autovacuum', or 'autovacuum_wraparound'),
respectively. This allows users and monitoring tools to better
understand VACUUM behavior.

Bump catalog version.

Author: Shinya Kato <shinya11(dot)kato(at)gmail(dot)com>
Reviewed-by: Kirill Reshke <reshkekirill(at)gmail(dot)com>
Reviewed-by: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Reviewed-by: Robert Treat <rob(at)xzilla(dot)net>
Reviewed-by: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
Reviewed-by: Sami Imseih <samimseih(at)gmail(dot)com>
Reviewed-by: Michael Paquier <michael(at)paquier(dot)xyz>
Reviewed-by: Yu Wang <wangyu_runtime(at)163(dot)com>
Discussion: https://postgr.es/m/CAOzEurQcOY-OBL_ouEVfEaFqe_md3vB5pXjR_m6L71Dcp1JKCQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/0d789520619803cf6629ebf980e116d733b6756f

Modified Files
--------------
doc/src/sgml/maintenance.sgml | 7 +++-
doc/src/sgml/monitoring.sgml | 75 ++++++++++++++++++++++++++++++++++++
src/backend/access/heap/vacuumlazy.c | 23 +++++++++--
src/backend/catalog/system_views.sql | 10 ++++-
src/include/catalog/catversion.h | 2 +-
src/include/commands/progress.h | 12 ++++++
src/test/regress/expected/rules.out | 14 ++++++-
7 files changed, 134 insertions(+), 9 deletions(-)