Showing city and zip in billing address even when missing a state

[dparker1005]

All Submissions:

• Have you followed the Contributing guideline?
• Does your code follow the WordPress' coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

Some addresses, such as those in Belgium, have cities and postal codes but not states. Currently in PMPro, if a state is not present, we do not show the city or postal code. This PR updates PMPro to account for these types of addresses.

Resolves XXX.

How to test the changes in this Pull Request:

1. Set up Stripe Checkout to always collect billing address
2. Check out using a Belgian billing address
3. See that city and zip were not shown in PMPro email/orders page before this PR, but are afterwards.

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you successfully run tests with your changes locally?

Changelog entry

Enter a summary of all changes on this Pull Request. This will appear in the changelog if accepted.