MB-10327 automated tests for limit on number of simultaneous moves

Change-Id: Id2d5d1600cb55a03b442df3824000668d4d32aff
Reviewed-on: http://review.couchbase.org/35694
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>