Add coverage in [Primary Storage - Object Storage - S3] "Deleted files continue to exist in bucket"

[joshtrichards]

Several open issues in nextcloud/server overlap with this matter:

• see those Issues for material/coverage ideas

• See docs for providers such as: AWS, Backblaze¹, etc.

Footnotes

1. "Buckets in Backblaze B2 are versioned by default. Because buckets are versioned, when a file is deleted by referencing the name, only the most recent version of that file is deleted and older versions of the file continue to exist in the bucket." -- https://www.backblaze.com/apidocs/introduction-to-the-s3-compatible-api ("Differences from AWS S3") ↩