fix(customer): add first and last name for company customers

[faisalahammad]

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Changes proposed in this Pull Request:

Closes #162

Company-type customers were generated without a first name or last name, so saving them through WooCommerce's customer data store failed with WC_Data_Exception: First name is a required field. Order generation creates customers as part of building an order, so wp wc generate orders crashed for affected users.

The fix generates a contact person name for company customers and includes it in both billing and shipping data, so the customer saves correctly. Person-type customers were already correct.

How to test the changes in this Pull Request:

1. With WooCommerce and Smooth Generator active on a default theme, run wp wc generate orders 10.
2. Run wp wc generate customers 10 --type=company.
3. Open one generated company customer and confirm the first and last name fields are populated.

Expected: orders and company customers generate without errors, and company customers have a contact name.

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
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Changelog entry

Fix fatal error when generating orders caused by company customers missing a first and last name.

FOR PR REVIEWER ONLY:

• I have reviewed that everything is sanitized/escaped appropriately for any SQL or XSS injection possibilities. I made sure Linting is not ignored or disabled.