Bug 7021: Patron category in the statistics table

Bug 7021: Patron category in the statistics table

This patch populates the koha.statistics.usercode with borrowers.categorycode where it is easily available.
Currently for statistics.type 'issue' OR 'localuse' OR 'renew'.

Supplied a script to UPDATE the old statistics records.

Have fun!

To test:
1. Add loan for patron.
2. Check statistics table
=> 'usercode' column for this issue should now contain patrons categorycode

To test add_statistics_borrowers_categorycode.pl:
1. Run add_statistics_borrowers_categorycode.pl
2. Check statistics table
=> all statistics which are type 'issue' OR 'localuse' OR 'renew'
should now contain patrons categorycode in 'usercode' column

Also prove that tests in t/db_dependent/Circulation.t still pass.

Rebased-by: Emmi Takkinen <emmi.takkinen@koha-suomi.fi>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>