feat: add compatibility with @golevelup/rabbitmq

[lucas-gregoire]

Description

@golevelup/nestjs is a really powerful library when using RabbitMQ with NestJS.
It's a way more advanced library compared to @nestjs/microservices for RabbitMQ integration.

Currently it's not compatible with nestjs-i18n because it uses an ExecutionContext type rmq which is not handled by nestjs-i18n.
This PR aims to use the ConsumeMessage as container for the i18nContext, to enable creating custom lang resolvers for RabbitMQ consumers:

import { ExecutionContext } from '@nestjs/common';
import { I18nResolver } from 'nestjs-i18n';

export class RabbitMqHeaderResolver implements I18nResolver {
  resolve(context: ExecutionContext): string | undefined {
    if (context.getType<string>() === 'rmq') {
      const consumeMessage = context.getArgs()[1] as ConsumeMessage;
      return message.properties.headers['x-lang'];
    }
    return undefined;
  }
}

It's not so simple to test this new feature as it requires to setup a RabbitMQ instance in tests.
But it's still possible to do something similar to this setup:

• https://github.com/golevelup/nestjs/blob/master/.github/workflows/ci.yml#L21-L30
• https://github.com/golevelup/nestjs/blob/master/integration/rabbitmq/e2e/execution-context.e2e-spec.ts

[coveralls]

coverage: 90.764% (-0.2%) from 90.925%
when pulling 85c491f on lucas-gregoire:feat/rmq-context
into a861a2f on toonvanstrijp:main.