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

Models/DeploymentJobStepModel.cs

@@ -34,6 +34,18 @@ namespace Microsoft.SelfService.Portal.Core.API.Models
         [Column(Order = 10)]
         public string? ApprovalComment { get; set; }
 
+        [Column(Order = 11)]
+        public DateTime? Started { get; set; }
+
+        [Column(Order = 12)]
+        public DateTime? Finished { get; set; }
+
+        [Column(Order = 13)]
+        public string? OutputMetadataJson { get; set; }
+
+        [Column(Order = 14)]
+        public string? ErrorMessage { get; set; }
+
         public QueueJobModel QueueJob { get; set; }
         public QueueJobStepModel? DependsOnQueueJobStep { get; set; }
     }