Bugfix/15678 user addresses and fields

[i-just]

Description

First issue:
User‘s nested addresses owned by a custom field appear in the main Addresses view when editing that user.

Fix:
User->getAddresses() should return user's "native" addresses - the ones linked via the addresses attribute and not via a custom Addresses field.

The above also fixes the issue where deleting the custom Addresses field caused an error about a missing field when visiting the user's Addresses screen.

Second issue:
After deleting an Addresses field, the fieldId is not cleaned up, nor are the nested elements deleted. Garbage collection also doesn't clear those out.

Fix:
This happens because there's no foreign key constraint on the addresses.fieldId field.
I added a migration that will delete all the addresses that are linked to a field that's been hard deleted and then add a foreign key constraint to the fieldId column. I also adjusted the Gc service to run partial elements deletion on Addresses.

Related issues

#15678

[i-just]

I moved it back to draft as there's a way to approach the second problem that is more consistent with what we already have in place.

[brandonkelly]

Went with a garbage collection-only approach so we can avoid adding a new migration, and because relying on cascading deletes was only a partial solution anyway (requiring deletePartialElements() to finish the job).