feat: Add pipeline support for batching multiple publish calls

[jgillick]

If a large number of publish calls need to be made, they call all be batched into a single HTTP request to redis with a pipeline.

This PR attempts to keep to keep the familiar redis pipelining API while supporting the PubSub config and serializer.

Basic Example

If you have a list to publish:

const pubSub = new RedisPubSub({ ... });

// Create pipeline
const pipeline = pubSub.pipeline();

[1,2,3,4,5,6].forEach((id) => pipeline.publish('Test', {id}))

// Execute the pipeline to redis
await pipeline.exec();

Chainable calls

If you have a specific number of publish calls to make at the same time:

const pubSub = new RedisPubSub({ ... });
await pubSub
  .pipeline()
  .publish('Test1', {})
  .publish('Test2', {})
  .publish('Test3', {})
  .exec();

[davidyaha]

@jgillick Thanks for the PR! I would love to merge it if you can make sure the format is unchanged on the tests file.
It looked like a lot of the changes there are unrelated to this pull request which caused conflicts unintentionally.

[jgillick]

@jgillick Thanks for the PR! I would love to merge it if you can make sure the format is unchanged on the tests file. It looked like a lot of the changes there are unrelated to this pull request which caused conflicts unintentionally.

Sorry about that. The file has been corrected to include only the new tests and supporting mocks.