Abstract type definition Core.Number as a super-type of all numeric types

Add type definition Core.Number  with underlying type Edm.PrimitiveType  annotated with Validation.DerivedTypeConstraint listing all numeric types (depends on  ODATA-1252 ), see https://github.com/oasis-tcs/odata-vocabularies/pull/224. Alternative: Types.Number  in new vocabulary, see https://github.com/oasis-tcs/odata-vocabularies/pull/225. A new Types vocabulary could also solve ODATA-220 ODATA-287 Alternatively we could add these types to the Core vocabulary, similar to Core.LocalDateTime   https://github.com/oasis-tcs/odata-vocabularies/pull/224 or https://github.com/oasis-tcs/odata-vocabularies/pull/225