Specify warning if sensor is not available

[TBSniller]

If a not available sensor name is put into the settings file, then a missleading warning is displayed:

Here as an example the default settings file (with CPU Temp for Intel based system) on a system with AMD CPU.

We should check if the sensor is available before using it.

[Budskex]

in the settings.json, for the CPU it shows "CPU Package" for the name, right?

you need to look for the "right" name on the available-sensors.json file.

for example, for me it was "Core (Tctl/Tdie)" to show the temp of my amd 7800x3d