add Analog measurements

[VladimirAlexiev]

@AndyKims @Sveino
statnett/Talk2PowerSystem#5 (comment) shows cim:Analog measurements.
This query on https://cim.ontotext.com/graphdb/sparql finds 30 measurements:

PREFIX cim: <http://iec.ch/TC57/2013/CIM-schema-cim16#>
PREFIX sesame: <http://www.openrdf.org/schema/sesame#>
select * { 
  [] a cim:Analog; 
    cim:IdentifiedObject.name ?measName;
    cim:IdentifiedObject.description ?measDescr;
    # cim:Measurement.measurementType ?type; # all are "ThreePhaseActivePower"
    cim:Measurement.PowerSystemResource [sesame:directType ?psrType; cim:IdentifiedObject.name ?psrName]
}

They are all about entsoe2:EnergyCongestionZone (entsoe2: <http://entsoe.eu/CIM/SchemaExtension/3/2#>):

#10 has removed entsoe2, and I can't find any Analog in this repo.
Please add measurements!