Add queue hardening by modifying DeploymentJobTargets, DeploymentJobSteps, and DeploymentJobs tables

- Drop existing indexes on DeploymentJobTargets and DeploymentJobSteps
- Alter Status column to nvarchar(450) in DeploymentJobTargets, DeploymentJobSteps, and DeploymentJobs
- Add new columns: Finished, OutputMetadataJson, Started to DeploymentJobTargets; ErrorMessage, Finished, OutputMetadataJson, Started to DeploymentJobSteps; CorrelationId, HeartbeatAt, Priority, RowVersion, ScheduledAt, WorkerName to DeploymentJobs
- Create new indexes for improved query performance
- Add constraints to ensure OutputMetadataJson is valid JSON
- Record migration in __EFMigrationsHistory

Dto/Deployment/Get/GetQueueJobStepDto.cs

@@ -11,6 +11,10 @@
         public DateTime? ApprovedAt { get; set; }
         public string? ApprovedBy { get; set; }
         public string? ApprovalComment { get; set; }
+        public DateTime? Started { get; set; }
+        public DateTime? Finished { get; set; }
+        public string? OutputMetadataJson { get; set; }
+        public string? ErrorMessage { get; set; }
     }
 }