Ci::AbortPipelinesService should fail jobs

Problem

Ci::AbortPipelinesService currently updates the status of pipelines/stages/jobs to canceled in bulk.

There is a fundamental difference between using canceled and failed + failure_reason. In case where jobs are dropped by the system we need to use failed and communicate the reason to the user through a failure_reason.

Solution

• introduce 2 new failure reasons :user_blocked and :project_deleted for the 2 cases where the service object is called
• Change Ci::AbortPipelinesService to take in input the failure reason and update the statuses to failed + failure_reason