Issue #3609636: Model order attributes as configurable fields on the order (Field UI, Views, form capture, field-backed matchers)

Implements #3609636.

Models order attributes as fields on the order (yoyaku_transaction), so a site decides what it captures and counts bookings by, with typed fields that are Views columns via core with no custom code.

• Field UI enabled on the order; booker_email and booker_name ship as base attribute fields; any configurable field an administrator adds participates by convention.
• A field-backed attribute matcher is derived once per attribute field (order_field:), replacing the hardcoded email matcher; value, match and capture all go through the field API.
• The webform booking handler maps submission elements (including composite sub-elements, e.g. address__city) onto order attributes; enforcement runs over every captured dimension.
• Renames the customer_* fields and terminology to booker_* (pre-1.0, no update hooks).
• Example module: birth_date and address elements mapped to configurable order fields, plus a minimum-age (18+) order constraint.

Docs and French translations updated. Kernel tests cover the field-backed matcher, an administrator-added field used as a matcher, and the card-token dimension.