* Adds addComposedMappedModels and testComposedSchemaOneOfDiscriminatorMap
* Requires that discriminators be required properties
* Strengthens discriminaotr validation, adds better error messages, adds schema oneof samples
* Adds oneOf and anyOf invalidDiscriminator tests
* Updates incorrect addOneOfInterfaceModel invocation
* Runs ensure-up-to-date
* Adds updates from Sebastien Rosset
* Removes newlines
* Uses df.isString
* Fixes tests be correctly setting df.isString
* Updates discriminatorExplicitMappingVerbose description per PR feedback
* Adds description of how mappedModels is populated
* Adds the suggestion exception raising when a MappedModel mappingName is null
* Actually resolves merge conflicts
* Switches two methods to package private because they are needed for testing
* Allow nulls in MappedModel.getMappingName
* Updates CLI flag name to legacyDiscriminatorBehavior, default=true
Co-authored-by: William Cheng <wing328hk@gmail.com>
