fix(ocpp2): audit TransactionEvent — state ownership, deauthorization, meter values

fix(ocpp2): audit TransactionEvent — state ownership, deauthorization, meter values

- Fix periodic TransactionEvent(Updated) to include meter values via buildMeterValue
- Replace non-UUID temp transactionId with generateUUID in OCPP20AuthAdapter
- Refactor state ownership: response handler is sole authority for transactionStarted,
  StatusNotification(Occupied), and TxUpdatedInterval start
- Add transactionPending flag to prevent duplicate RequestStartTransaction race conditions
- Add requestDeauthorizeTransaction per E05.FR.09/FR.10/E06.FR.04: sends
  Updated(Deauthorized, SuspendedEVSE) then Ended(Deauthorized, DeAuthorized)
- Fix rejection check to cover all non-Accepted idTokenInfo statuses
- Extract buildFinalMeterValues helper to eliminate DRY violation
- Skip Occupied/TxUpdatedInterval setup when idToken is rejected in same response
- Remove cleanup from Ended response handler (owned by caller)
- Add tests for getTxUpdatedInterval, requestDeauthorizeTransaction, Updated-failure path