Show different unit options in compare view

[markoaamunkajo]

Description:

Users currently set global unit settings and cannot be able to compare different available units in compare view.

Let's add options to list to compare:

Temperature (°C)
Temperature (°F)
Temperature (K)
Humidity (relative, %)
Humidity (absolute, g/m3)
Humidity (dew point, °)
Pressure (pascal, Pa)
Pressure (hectopascal, hPa)
Pressure (inch of mercury, inHg)
Pressure (millimetre of mercury, mmHg)