Add the --keep-archive option to the crowdin download command

[andrii-bodnar]

The crowdin download command currently removes the downloaded ZIP archive with translations after extracting.

But sometimes it would be helpful to keep this ZIP file to somehow post-process it. For example, use as an artifact in some CI/CD integrations.

I'm suggesting adding an optional --keep-archive option to the crowdin download command. When this option is specified, the CLI shouldn't remove the downloaded ZIP archive with translations.

The -h description for this option: Do not remove the downloaded archive with translations after it's extracting

This new option should be applied only to the crowdin download command and not to its subcommands.