IfcIonConcentrationMeasure inconsistency

The unit for `IfcIonConcentrationMeasure` has changed in IFC4x3 from `mg/L` to `mol/m3`.

Cfr.
https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcIonConcentrationMeasure.htm

In IFC this is not a problem because derived units characterise the unit fully, but we need to be aware of such difference in IDS.

https://github.com/buildingSMART/IDS/blob/016bbadce0d227d8eabbbc3e8b2b3788590b8a97/Documentation/UserManual/units.md?plain=1#L35

How do we want to fix this?
- [ ] I suppose that we should fix the inconsistent exponent `mol/m3` does not match `(-3, 1, 0, 0, 0, 0, 0)`, it should be `(-3, 0, 0, 0, 0, 1, 0)`
- [ ] Should we also document the change and provide a warning?
- [ ] Do we need to add an auditing tool constraint to prevent value specifications on such measure if applied across [4x3] and [2x3,4]?
- [ ] perhaps add a column to the table to identify the relevant schemas and duplicate the line with the two units.