Improve dry-run for manual invocation

[badboy]

When adding new libraries/apps we recommend doing a dry-run to ensure probe-scraper is working as expected and without issues.
This however requires deep knowledge about probe-scraper and how it works and with the push-mode it even requires a bit of understanding of that.

Just now we had an issue where a dry-run performed (#645) was fine, until it hit production.
Subsequently I found the "correct" dry-run (#649 (comment)) and that then failed the same as in production.

We should have some mode that automatically does the right thing (pick all dependencies) and document that. Maybe even be able to run that on CI.