chore(graphql): expose complete options

[mattia-lau]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

complete options is not expose

Issue Number: 3164

What is the new behavior?

expose complete options

Does this PR introduce a breaking change?

• Yes
• No

Other information

alternative approach to integrate ApolloServer and NestJS(createApplicationContext), without making any big refactoring in current codebase

import { ApolloServer } from '@apollo/server';
import {
  LambdaHandler,
  handlers,
  startServerAndCreateLambdaHandler,
} from '@as-integrations/aws-lambda';
import { ApolloFederationDriver, PluginsExplorerService } from '@nestjs/apollo';
import { ModulesContainer, NestFactory } from '@nestjs/core';
import { GraphQLModule, extend } from '@nestjs/graphql';
import { AppModule } from './app.module';

const requestHandler = handlers.createAPIGatewayProxyEventV2RequestHandler();

let serverless: LambdaHandler<typeof requestHandler>;

const app = await NestFactory.createApplicationContext(AppModule, {
  logger: ['error'],
});

await app.init();

const  { completeOptions } = app.get(GraphQLModule);

const options = extend(completeOptions, {
  plugins: new PluginsExplorerService(moduleContainer).explore(
    completeOptions
  ),
});

const server = new ApolloServer(options);

const handler = startServerAndCreateLambdaHandler(server, requestHandler, {});

[mattia-lau]

@kamilmysliwiec