Fix enums and input objects in a more clever way

They're basically being specified as return values (i.e. on the ruby
side of the ruby/wire-format divide) so coerce them to results before
validating. Also fix InputObject#coerce_result to handle camelizing
keys.

I _think_ this makes sense?

lib/graphql/schema/argument.rb

@@ -317,7 +317,8 @@ def validate_input_type(input_type, wrapped: false)
       end
 
       def validate_default_value(default_value, input_type)
-        raise "BOOM" unless input_type.valid_input?(default_value, GraphQL::Query::NullContext.new)
+        default_value = input_type.coerce_isolated_result(default_value) unless default_value.nil?
+        raise "BOOM" unless input_type.valid_isolated_input?(default_value)
       end
 
       def validate_deprecated_or_optional(null:, deprecation_reason:)

lib/graphql/schema/input_object.rb

@@ -226,8 +226,8 @@ def coerce_input(value, ctx)
         # It's funny to think of a _result_ of an input object.
         # This is used for rendering the default value in introspection responses.
         def coerce_result(value, ctx)
-          # Allow the application to provide values as :symbols, and convert them to the strings
-          value = value.reduce({}) { |memo, (k, v)| memo[k.to_s] = v; memo }
+          # Allow the application to provide values as :snake_symbols, and convert them to the camelStrings
+          value = value.reduce({}) { |memo, (k, v)| memo[Member::BuildType.camelize(k.to_s)] = v; memo }
 
           result = {}