Improve logging of auto-vacuum and auto-analyze

Improve logging of auto-vacuum and auto-analyze

When logging auto-vacuum and auto-analyze activity, include the I/O
timing if track_io_timing is enabled.  Also, for auto-analyze, add the
read rate and the dirty rate, similar to how that information has
historically been logged for auto-vacuum.

Stephen Frost and Jakub Wartak

Reviewed-By: Heikki Linnakangas, Tomas Vondra
Discussion: https://www.postgresql.org/message-id/VI1PR0701MB69603A433348EDCF783C6ECBF6EF0%40VI1PR0701MB6960.eurprd07.prod.outlook.com