Improve the local extraction process

[diptanu]

Currently when a developer runs the following command to extract from an extractor which has not been downloaded yet, they have to download the container themselves, the indexify extract command doesn't do that. Secondly the container can't be run twice unless a user deletes the container using docker rm manually and invokes extract again.

1. Indexify should download the container if it doesn't exist
2. Indexify should remove the older container first before it creates a container.