Applying the factor/rate twice may loose precision if one of the number is a rational with recurring decimal. Closes #14501 (grafted from 09e3674f3ffe90f74cf2bc8a9884e885b28c93b8) --HG-- branch : 7.0
For short label, we only use UoM with an help text showing with capital letter the meaning of UoM.
Closes #11867