Support Uploads inside of Input Types

[mfinley3]

It does not appear the gateway supports upload types nested as fields inside of Inputs

It would be a nice feature to have as frameworks such as https://github.com/99designs/gqlgen support this.

scalar Upload

input FilesInput {
	files:   [Upload!]!	# appears to be unsupported
	file:    Upload!	# appears to be unsupported
}
type Mutation {
	upload(file: Upload!): String!	                        # supported
	uploadMulti(files: [Upload!]!): [String!]!	        # supported
	uploadMultiInput(input: FilesInput!): [String!]!	# unsupported
}

A few tweaks to: https://github.com/nautilus/graphql would be needed for this as well