feat(OCPP21): Add NotifyAllowedEnergyTransferReqRep (#197)

Signed-off-by: Martin Litre <mnlitre@gmail.com>

Author: mlitre

everest-testing/src/everest/testing/ocpp_utils/charge_point_v21.py

@@ -359,3 +359,7 @@ async def unpublish_firmware_req(self, **kwargs):
     async def update_firmware(self, **kwargs):
         payload = call.UpdateFirmware(**kwargs)
         return await self.call(payload)
+
+    async def notify_allowed_energy_transfer_request(self, **kwargs):
+        payload = call.NotifyAllowedEnergyTransfer(**kwargs)
+        return await self.call(payload)