Fixed OCPP connector failing to load on ocpp 2.x

[cafe-jun]

Closes #1908

Problem

The OCPP connector cannot be imported at all on current versions of the ocpp library:

File "/thingsboard_gateway/connectors/ocpp/charge_point.py", line 64, in ChargePoint
    @on(Action.BootNotification)
AttributeError: type object 'Action' has no attribute 'BootNotification'.
Did you mean: 'boot_notification'?

ocpp 1.0 deprecated two things and 2.0 removed them:

• the PascalCase Action enum members, in favour of snake_case
• the Payload suffix on call / call_result classes

The 1.0 source says so explicitly:

Action enum contains deprecated members and will be removed in the next major release, please use snake case members.

requirements-full.txt lists ocpp unpinned, so any fresh install resolves to 2.x and the connector is dead on arrival. TBModuleLoader reports the import failure and no OCPP device can connect.

Change

Renamed 16 references across two files to the current API:

before	after
Action.BootNotification	Action.boot_notification
call_result.BootNotificationPayload	call_result.BootNotification
call.DataTransferPayload	call.DataTransfer

…and the same for Authorize, Heartbeat, MeterValues, DataTransfer.

This does not drop ocpp 1.x support

Both spellings exist in 1.0, so the new names resolve there too. No version pin is needed and no existing install breaks.

The enum values are also identical, so nothing changes at runtime:

>>> Action.meter_values.value        # ocpp 1.0.0 and 2.1.0
'MeterValues'

That matters because Action.meter_values is passed through as messageType to the uplink converter — the converter still receives the same string it did before.

Verification

Imported charge_point and ocpp_connector against three library versions:

ocpp	before	after
1.0.0	imports	imports
2.0.0	AttributeError	imports
2.1.0	AttributeError	imports

So the change strictly widens the supported range rather than shifting it.

Notes

• No tests added: there is no OCPP coverage under tests/ today. Happy to add an import smoke test if you would like one in this PR.
• I did not pin ocpp in requirements-full.txt, since the connector now works on both major versions. Let me know if you would rather have a lower bound recorded there anyway.
• Only the names the connector actually uses were touched. I did not sweep the rest of the OCPP surface for other deprecations.