Filtering Shelly and tasmota energy values and storeing them in an optimized way on the device.

[eckelj]

Shelly's device status logs are up to 700 bytes in size. We will have to reduce this and will only store:
Time, temperature, and energy tags of the JSON struct.
In addition to that, we will also store the values only (it's a fixed order and a fixed value set, and recreate the json object on demand.