This patch add a configurable timeout after which the sharder
will warn if a container DB has not completed sharding.
The new config is container_sharding_timeout with a default of
172800 seconds (2 days).
Drive-by fix: recording sharding progress will cover the case
of shard range shrinking too.
Co-Authored-By: Alistair Coles <alistairncoles@gmail.com>
Change-Id: I6ce299b5232a8f394e35f148317f9e08208a0c0f