Switch to using year of birth for patient transfer confirmation

[rithviknishad]

Proposed Changes

• Switch to using year of birth for patient transfer confirmation

Associated Issue

• Required by: change date of birth field to year of birth in patient registration form care_fe#7574
• FE: Switch to using year of birth for patient transfer confirmation care_fe#7575

Merge Checklist

• Tests added/fixed
• Update docs in /docs
• Linting Complete
• Any other necessary step

Only PR's with test cases included and passing lint and test pipelines will be reviewed

@coronasafe/care-backend-maintainers @coronasafe/care-backend-admins