Feature/Handle Meter Value Cost Update

[lydiazcheng]

Context

If sendCostUpdatedOnMeterValue is true, meterValues handler should trigger cost update

Changes

1. Add checks for sendCostUpdatedOnMeterValue config and meterValue context in the meterValues handler. If they are true and ReadingContextEnumType.Sample_Periodic, handler stores the transactionDbId in meterValue record. And then it triggers a CostUpdated request.
2. Update the totalCost in database.
3. Fix missing last meterValue problem when creating a new meterValue in db and then reading all meterValues.

Test

1. In config, remove costUpdatedInterval and set sendCostUpdatedOnMeterValue to true.
2. Create a tariff for charger.
3. Charger sends TransactionEvent with "eventType":"Started" to start a new transaction
4. Charger sends MeterValues
5. Citrine responds the request and sends a CostUpdated req containing the totalCost
6. The totalCost is updated in db.

[thanaParis]

Approved