Bug 32835: Fix cataloguing/value_builder/unimarc_field_122.pl

Bug 32835: Fix cataloguing/value_builder/unimarc_field_122.pl

Use event parameter

This is part of the refactoring happening in bug 30975

Test plan:
1. Verify that the plugin continues to work as before

Signed-off-by: David Nind <david@davidnind.com>
https://bugs.koha-community.org/show_bug.cgi?id=32825
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit e557357e62b6d8655f40cd576a8de846a687abf1)
Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>
(cherry picked from commit 256b329850e6c0a080d905ec81fa3c40d6e91c30)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
(cherry picked from commit bafbe0c1b707d3cec50c184b52d08bd442deff0f)
Signed-off-by: Arthur Suzuki <arthur.suzuki@biblibre.com>