Scout : Change default queue at import time

[ybert]

As we currently do with chunks using the -c option, we could introduce a -q option to specify a different queue for the import process.

This would help address issues when handling high-volume live data with the library. When we modify our Searchable model, we need to re-import the entire database. With over 100 million documents to process, we don’t want new live data saved by users to be delayed in the queue until all import jobs are completed.

A simple solution would be to use separate queues: one for live data saved by users and another for import jobs.