Bug 14246: Add borrowernumber, altered SQL

Bug 14246: Add borrowernumber, altered SQL

As suggested by kind reviewers, an AFTER statement was added to the atomic
upgrade script to ensure that the final field order is consistent is both
fresh and upgraded databases.

Also:
* UPDATE action changed to CASCADE to improve robustness.

Test plan:
* Apply first patch in this set.
* Apply this patch.
* Perform a database upgrade.
* Use mysql client to inspect field order.
  It should be identical to the kohastructure.sql order.

Sponsored-by: Halland County Library
Signed-off-by: Nick Clemens <nick@quecheelibrary.org>
Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>