Changing hierarchy and axiomatization of CHMO:concentration

[StroemPhi]

Once #13 is resolved we should think about making CHMO:concentration a IAO:scalar measurement datum, as it seems to always be that and to also add the SubclassOf IAO:'is about' some PATO:'concentration of'. According to OBO practices, the latter would presumably entail having to obsolete the existing term and mint a new one, due to this semantic change. Similarly the children of concentration should also have a SubclassOf axiom that relates them to their respective PATO qualities.

Also needed are annotations (or SSSOM TSV) for the mapping to:

• SIO:concentration
• EDAM:Concentration
• NCIT:Concentration
• AFO:concentration