AssertDeleteNonexistentWorks asserts that `s3cli delete` on a non-existent object exits with status 0 (tests idempotency).

AssertGetNonexistentFails asserts that `s3cli get` on a non-existent object will fail.

AssertLifecycleWorks tests the main blobstore object lifecycle from creation to deletion.

AssertOnSignedURLs asserts on using signed URLs for upload and download.

AssertPutOptionsApplied asserts that `s3cli put` uploads files with the requested encryption options.

GenerateRandomString generates a random string of desired length (default: 25).

MakeConfigFile creates a config file from a S3Cli config struct.

MakeContentFile creates a temporary file with content to upload to S3.

RunS3CLI runs the s3cli and outputs the session after waiting for it to finish.