Updates an existing billing line with new parameters.

This endpoint can be used to modify the amount, frequency, description, or
transaction configuration for a billing line. Changes to billing lines will
affect future billing cycles, but will not modify existing transactions
that have already been processed.

If you change the transaction_configuration_id, the system will automatically
recalculate and update the associated debit and credit accounts based on the
new configuration using the BillingLineFactory service.

The factory ensures that all accounting-related updates maintain proper
financial consistency according to the configuration rules.

When updating critical financial parameters, care should be taken as this
may affect financial reporting and revenue recognition.