Barcode validation has been reorganized so the system can verify check digits more consistently across barcode-related workflows. This internal cleanup helps prepare barcode scanning for future GS1-128 support while preserving existing behavior through added test coverage.

Refactor the way barcode nomenclature verifies the barcode check digit in order to prepare the support of GS1-128 encoded barcode.

task-1968113

Event-related access control files were reorganized and renamed consistently across event modules. Security tests were moved into the full event test suite so future permission changes in related modules can be checked more reliably.

Purpose
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In event, many files have different naming format. We want to clean
them, to group the lines by models before changing and adding a new
event group.

Task ID-2204364
COM PR odoo/odoo#65867
Migration odoo/upgrade#2150