Support locale-based name field ordering in sign-up form (family name before given name)

[centerfield77]

Currently, the sign-up form always displays name fields in the order "First name, Last name". In many locales (e.g., Japanese, Chinese, Korean), the conventional order is family
name first, followed by given name.

It would be great if AuthKit could reorder the name fields based on the user's locale, or provide a configuration option to control the field order.

Expected behavior:

• For locales where family name comes first (e.g., ja, zh, ko), display the fields as: Family name → Given name
• For other locales, keep the current order: Given name → Family name

Why this matters:

• Users in these locales may be confused by the reversed order, leading to incorrect name entry
• This is a common i18n best practice followed by major platforms (e.g., Google, Apple)