new power-prices

[ArveVM]

create template for additional cost on electricity-spot

https://www.morenett.no/nyhende/auke-i-nettleiga-fr-1juli

add template to powersaver-integration as additional cost

add dockumentation in powersaver/change

inform Erlend of changed sensor-data - so that the actual documentation on prizealanyzer is updated

• or possibly create PR for priceanalyzer??