[evcc] API change on duration channels

[MikeTheTux]

Since EVCC version 0.127.0 (evcc-io/evcc#13319) the EVCC Rest API duration states are in seconds instead of nanoseconds.

Current EVCC implementation still treats them as Nano-Seconds. E.g.:

        long chargeDuration = loadpoint.getChargeDuration();
        channel = new ChannelUID(uid, channelGroup, CHANNEL_LOADPOINT_CHARGE_DURATION);
        updateState(channel, new QuantityType<>(chargeDuration, MetricPrefix.NANO(Units.SECOND)));