Removed useless line from checks.hpp
Changed the order of conditions in DataArray validation
new util isScalable-vector overload & isSetAtSamePos vector comparison

isScalable now has a vector overload that compares all units at the same vector positions, while isSetAtSamePos checks whether either both strings in two string-vectors are not set or both are set.
new helper function that gets all units of all dims of given DataArray
Changed checks for ref units & unit helper classes not needed anymore

The tagRefsHaveUnitsand and tagUnitsMatchRefsUnits now are using the new helper & util functions and thus don't need the "Units" helper class & "hasUnit" helper struct.