hapi: Switch uploads to receive "raw" request and response.

The immediately pressing reason is to align on the same types that the
`processRequest` method from `graphql-upload` (aliased here as `processFileUploads`) uses.

Using the raw types should be fine as `graphql-upload` only binds to
the `response` to receive "close"-like `EventEmitter` events, and uses the
`request` side for the piping of data, which should be identical to Hapi's
abstraction.

Helps-to-land: #2844

packages/apollo-server-hapi/src/ApolloServer.ts

@@ -23,8 +23,8 @@ function handleFileUploads(uploadsConfig: FileUploadOptions) {
     ) {
       Object.defineProperty(request, 'payload', {
         value: await processFileUploads(
-          request as any,
-          request.response as any,
+          request.raw.req,
+          request.raw.res,
           uploadsConfig,
         ),
         writable: false,