Add additional_temperatures feature

[Smankusors]

mostly I copy pasted from external drives sensors logics 😅

I needed this because my Rock Pi 4 has a cpu sensor name. While I think that could be as simple as adding it to the whitelist, I have a plan to buy a different SBCs, that might also have different sensor name... Also, I want to install this on several Android devices, because I want to track their battery temperatures

btw, other changes:

• remove old comment about the old way of reading temperature (git already has history for this, so we don't need it anymore?)
• refactor the sensor enabled checking on a separate function
• refactor get_temp so that it can read other temperatures

let me know if you need anything else 😉