Provide an option to download DB without caches

[deiviic]

When downloading database, if production hasn't had caches cleared in a while, the database size gets quite big. It would be beneficial to have an option provided in the release information to download database without cache and session data, without having to clear production caches and impacting performance of the site.

Downloading database (without cache):
ssh {{ include "drupal.shellHost" . }} -J {{ include "drupal.jumphost" . }} "drush sql-dump --structure-tables-list=cache,cache_*,history,search_*,sessions" > my_database_dump.sql

--structure-tables-list flag instructs to keep the tables but not to download the data.

This could be added as an additional download option, not a replacement of the original one.