SYSML17 — move to SystemOfQuantities

this
[1] The query accessibleQuantityKinds() gives all the QuantityKinds directly defined in the SystemOfQuantities or transitively in any included or used SystemOfQuantities.
allAccessibleQuantityKinds() : QuantityKind[0..*]

body: allAccessibleSystemOfQuantities()>collect(quantityKind)>flatten()->asSet() inv SoU3_3: getEffectiveSystemOfQuantities() = null or let aqk : Set(QuantityKind) = getEffectiveSystemOfQuantities().allQuantityKinds() in ->allUnits() ->forAll(u | aqk>includesAll (getKindOfQuantitiesForMeasurementUnit(u)))

should be under SystemOfQuanties