Update consumed until when deleted consumption
Sometimes we have to stop a subscription before its last consumption (usually customer inform to stop when he receives the invoice). For that user can delete consumptions if it was not yet invoiced. But he can not set an end date earlier because the "consumed until" is still based on the last consumption deleted. For me when deleting consumption (or update) we must trigger a re-computation of the "consumed until" field. Also I think the next consumption date should be updated. Indeed one of the two fields could be a Function field.