Allow configuring and overriding the path for the exported files

Hey @murz,

The [drupal_root]/scs-export is a fallback path if you don't mention the custom one.

e.g.

drush content:export node /relative/output/path

Yay, that's good! Then, would be great to allow configuring the default path in the module settings, to not pass it manually in each drush command.

yeah, makes sense, feel free to extend existing configuration form

I created an MR https://git.drupalcode.org/project/single_content_sync/-/merge_requests/144 with this feature - please check.

Rebased the MR over the latest commits in git.