Importer: Import should stop if failed to import a blob
Problem
This is a followup from !354 (comment 409783183).
The import tool supports a flag to allow importing all existing blobs, even if unreferenced. When activated, the import tool will start by importing these blobs. Currently, we have no tests to ensure that if a blob fails to be imported, the import will stop instead of continuing with the next blob.
Solution
If a blob fails to be imported, the import process should stop. We should add a test case for this scenario.
Edited by João Pereira