[6.x] Fix blueprint assignment of entries using custom entry class

[daun]

Fixes#15016

Issue

Localizing an entry can assign the wrong blueprint to the localization if two conditions are met:

• the collection has multiple blueprints
• the collection uses a custom entry class

This will lead to the default blueprint of the collection being assigned, instead of the origin entry's blueprint. The blueprint is not resolved because at the point of newing up the custom entry class, no origin is set.

Fix

Assigning the origin before the collection during localization allows resolving the correct blueprint.