Add sidekiq worker to populate token status

Problem to solve

Once a Secret Detection Vulnerability has been record in the database, the status of the detected token must be checked and stored.

Proposal

Add a sidekiq worker that iterates through tokens in the SD report and checks the status of the GitLab tokens.

Implementation Plan

• Create feature flag which defaults to false - Added in Add Backend Support for finding_token_status (!186220 - merged) • Radu Birsan • 17.11
• returns if the feature flag is not set to true
• returns if the project has not opted in this is part of [Beta] Validity checks (&16927) • Serena Fang • 18.6
• Gets the token status for GitLab PAT found in the pipelines report
• Gets the token status for all GitLab tokens found in the pipelines report - Moved to Add Secret Detection token status to all other ... (#534788 - closed) • Craig Smith • 18.2 • On track
• Saves those statuses to secret_detection_token_status linking them to vulnerability_occurrence
• Determine an appropriate concurrency_limit for the UpdateTokenStatusWorker - handled by Determine an appropriate concurrency_limit for ... (#535378) • Unassigned • 18.7
• What should the status of a nil token be? - discussed in #524544 (comment 2425943129). They are set to unknown.