Show amount at trips if no customer is visible

Employees must record their trips for internal claims. To keep the process simple, they do not have to select a customer or project in the process.

Currently, however, when these fields are removed from the registration screen and thus no customer is selected, no amount is visible on the summary page. However, these amounts are needed for internal administration and payment.

Currently, employees still have to select a customer, which is an extra action. We would like this to be unnecessary, and the default amount from 'Settings > Rides' to be used automatically.