Renaming driver/class to match product/repo name.

[kattni]

This renames the driver and the class to match the product description and the repo name. References to the original name have been updated.

This will require the guide be updated. Once this is merged I will attend to that.

[caternuson]

Looks good. For future ref, here's the background on this. Sensor part number decoder ring:

SHT3x-yyy-c

x: 0=low-cost, 1=standard, 5=high-end
yyy: ARP=analog, DIS=digital
c: B=bare, F=filter membrane, P=protective cover

PID2857 uses a SHT31-DIS-F. Product page calls it a "SHT31-D". Decided to have the module and class name match this better.