Add stats_reset to pg_stat_all_{tables,indexes} and related views

Add stats_reset to pg_stat_all_{tables,indexes} and related views

It is possible to call pg_stat_reset_single_table_counters() on a
relation (index or table) but the reset time was missing from the system
views showing their statistics.

This commit adds the reset time as an attribute of pg_stat_all_tables,
pg_stat_all_indexes, and other relations related to them.

Bump catalog version.
Bump PGSTAT_FILE_FORMAT_ID, as a result of the new field added to
PgStat_StatTabEntry.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Sami Imseih <[email protected]>
Reviewed-by: Michael Paquier <[email protected]>
Discussion: https://postgr.es/m/[email protected]