* Add support for PRESSURE_CBAR (centibars). This is the standard UOM for tensiometers.
While the data could be converted into something like MBAR, and displayed
like that, the correct UOM for this type of sensor is CBAR. Displaying
it as MBAR would be the same as displaying air pressure as feet of Hg, while
technically correct, it's hard to understand when reading.
Adding support for this UOM will fix errors in the UI(statistics) about the unit not
matching a unit of the device_class.
* Add tests for PRESSURE_CBAR
