Add `get_energy_prices` service call

[TheFes]

Is your feature request related to a problem? Please describe.
I am the author of the cheapest_energy_hours macro which can be used to determine eg the best time to turn on your dishwasher.
However, if you want to turn it on overnight, you loose today's data at midnight (as it will become yesterdays data then).

Some core integrations, like easyEnergy provide a service call in which you can get the data for the period you want, including historical data.

Describe the solution you'd like
Add support for the service call mentioned above

Describe alternatives you've considered
Add an additional attribute with the data of yesterday.

Additional context
NA

[Hellowlol]

Hi,

I do not want to add more attributes with a lot of data to the sensors, it already quite heavy. The only way would be to rewrite the addon so it uses a more "modern" approach where each attribute is a separate sensor. Unfortunately, I do not have time to do this now.

If someone want to contribute, please feel free to work on this.