Check name contains at least one letter

[rjlynch]

We have a claim on production with a surname of ".", we want to ensure
that the claimant's name includes at least one letter!

[github-actions]

Deployments

Journey	URL
Additional Payments	https://claim-additional-payments-for-teaching-review-3465-web.test.teacherservices.cloud/additional-payments/claim
Student Loans	https://claim-additional-payments-for-teaching-review-3465-web.test.teacherservices.cloud/student-loans/claim
Further Education	https://claim-additional-payments-for-teaching-review-3465-web.test.teacherservices.cloud/further-education-payments/landing-page
Early Years Payment	https://claim-additional-payments-for-teaching-review-3465-web.test.teacherservices.cloud/early-years-payment/landing-page
Relocation Payments	https://claim-additional-payments-for-teaching-review-3465-web.test.teacherservices.cloud/get-a-teacher-relocation-payment/landing-page
Admin	https://claim-additional-payments-for-teaching-review-3465-web.test.teacherservices.cloud/admin