The serialization context should materialize deferred types

lib/literal/serialization_context.rb

···
 	attr_reader :kind
 
 	def serialize(value, type:, strict: true)
+		type = type.materialize if type in Literal::Types::DeferredType
+
 		serializer = serializer_for_type(type)
 
 		if strict && !(type === value)
···
 	end
 
 	def deserialize(value, type:, strict: true)
+		type = type.materialize if type in Literal::Types::DeferredType
+
 		serializer = serializer_for_type(type)
 
 		if strict && !(_JSONData === value)

lib/literal/types/deferred_type.rb

···
 		"_Deferred"
 	end
 
+	def materialize
+		@block.call
+	end
+
 	def ===(other)
 		@block.call === other
 	end