Extract application of enterprise fees as adjustments into its own class
Rename method
Find EnterpriseFees with per-item calculators
Rename create_adjustments_for to create_line_item_adjustments_for, only show per-item fees
Create per-order adjustments with EnterpriseFeeApplicator
Find enterprise fees with per-order calculators
Find exchanges with any of a number of variants
EnterpriseFee.clear_all_adjustments_on_order clears adjustments from per-order fees
Charge per-order fees on orders exactly once
Spec fees_for only sums per-item fees
Sort enterprises by name on enterprise fees admin page