ViaductExtendedSchema appliedDirectives additional test cases for args and scalars

[`ViaductExtendedSchemaContract`](https://github.com/airbnb/viaduct/blob/5606d33876581c230471586e511c17ff1abdac71/shared/viaductschema/src/main/kotlin/viaduct/graphql/schema/test/ViaductExtendedSchemaContract.kt) should include tests that cover args and scalars.