"Profile Copy" feature is not working properly

[elisseck]

This was discovered in the process of getting functional tests running. The features related to

commerce_customer_ui.test:

• testCommerceCustomerUIProfileCopy()
• testCommerceCustomerUIProfileCopyDefaultEnabled()

Are not working in practice, or in tests. I commented out the tests for now because I think they'll need to be rewritten anyways once the feature is fixed up, given the way they're failing.