TSP-1694: add Order content type

[igorp1]

Summary

• add the missing content attribute to the Order interface
• model its documented values as managed | self_managed
• update typed Order fixtures to cover both values

Testing

• corepack yarn test src/booking/Orders/Orders.spec.ts
• corepack yarn build:test
• corepack yarn eslint src/booking/Orders/OrdersTypes.ts src/booking/Orders/mockOrders.ts

Slack Thread