Report progress of streaming base backup.
This commit adds pg_stat_progress_basebackup view that reports
the progress while an application like pg_basebackup is taking
a base backup. This uses the progress reporting infrastructure
added by
c16dc1aca5e0, adding support for streaming base backup.
Bump catversion.
Author: Fujii Masao
Reviewed-by: Kyotaro Horiguchi, Amit Langote, Sergei Kornilov
Discussion: https://postgr.es/m/
9ed8b801-8215-1f3d-62d7-
65bff53f6e94@oss.nttdata.com