Fixing State class and device class missmatch #288

[frli4797]

Fixing #288 by simply setting state class to SensorStateClass.TOTAL.

[kandsten]

I'd argue that this is in fact the wrong fix; what the integration is providing isn't a Total, it's a Measurement. It's a bit annoying that HA makes a strong assumption that device_class Monetary == always a Total value (i.e running tab), but it seems to me that it'd make more sense to drop the device_class altogether, keep state_class measurement and voilà, hourly prices get stored to LTS, warning goes away. Presenting it as total will also store the data to LTS, but it'll be junk.

I may be missing something really obvious here, of course, not having looked excessively at the code base.

[Hellowlol]

I dont use this feature so i havnt looked into it. Please send a pr if you think you have a better solution

[kandsten]

Roger wilco. May be a day or three, but I'll see about testing it properly and sending a PR once done.

[StSaens]

Came here after the recent changes in HA wrt long term statistics.
State class total is wrong for nordpool (https://developers.home-assistant.io/blog/2021/05/25/sensor_attributes?_highlight=state_class#state_class)

State_class should be measurement (given the options) and maybe device_class should be removed (to allow for state_class=measurement to be allowed)