Bug 7317: Add SQL templates & sysprefs.

Bug 7317: Add SQL templates & sysprefs.

* installer/data/mysql/atomicupdate/ill_tables.sql: New file.
* installer/data/mysql/kohastructure.sql: Add tables.
* installer/data/mysql/sysprefs.sql: Add sysprefs.
* installer/data/mysql/userflags.sql: Add userflags.
* koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/admin.pref:
  Add sysprefs to UI.

Signed-off-by: Magnus Enger <magnus@libriotech.no>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Benjamin Rokseth <benjamin.rokseth@kul.oslo.kommune.no>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>