Plugins that help to pass credentials for S3 and GCS to remote cluster workers

I didn't find a simple way to pass credentials to remote workers, such as S3 and GCS, while both are widely used to store data frames.
In this ticket's scope, I propose creating plugins that will help distribute the required keys to remote workers.

**GCP credentials**
GCP credentials file path is stored in `GOOGLE_APPLICATION_CREDENTIALS` env variable. The plugin has to create a remote file and pass an env variable with a proper path to workers.

**S3 credentials**
Like GCP, we must update credential files and store them on each worker.

PR: #439