MB-10073: improved UI/js for xdcr pause-resume

Change-Id: Ibebf9f39caf24a76b47f1431b3e9cb2989500fce
Reviewed-on: http://review.couchbase.org/33792
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>