Scalars lose their directives, including @specifiedBy #864

Scalars are built in SchemaClassScanner from the GraphQLScalarType passed to .scalars(...), but only its name, description and coercing are copied. Directives from the SDL are never applied, on the scalar or on its extensions:

scalar Date @specifiedBy(url: "https://example.com/date")

prints as scalar Date. The provided scalar's own specifiedByUrl and directives aren't copied either.

Probably easiest to build scalars in SchemaParser like the other types, so they go through directivesOf and SchemaDirectiveWiring too.