Set BulkImports::Tracker as skipped if entity is failed

Whenever GitLab Migration fails, for each entity trackers we create failure rows in the database with message 'Failed entity status'. This can be confusing because the corresponding pipelines for these trackers were not executed and they are technically skipped.

Skip such trackers instead of marking them as failed and don't create database records for these cases. They are not helpful during debugging into what went wrong during the migration.

Example: