Allow alter of user_data in openid_connect_userinfo_alter

Problem/Motivation

I would like to rewrite the sub property of an IDP. But it is only possible, to change the property in $userinfo but not in $user_data. This leads to an error later on, because modules compares the sub from both arrays.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes