Bring back null ids that Raven persistence relies on

Author: rbev

src/ServiceControl.AcceptanceTests/Recoverability/MessageFailures/When_a_retry_fails_to_be_sent.cs

@@ -27,7 +27,7 @@ class When_a_retry_fails_to_be_sent : AcceptanceTest
         [CancelAfter(180_000)]
         public async Task SubsequentBatchesShouldBeProcessed(CancellationToken cancellationToken = default)
         {
-            FailedMessage decomissionedFailure = null, successfullyRetried = null;
+            FailedMessageView decomissionedFailure = null, successfullyRetried = null;
 
             CustomizeHostBuilder = hostBuilder =>
             {
@@ -56,9 +56,9 @@ await Define<MyContext>()
                         return false;
                     }
 
-                    var decomissionedFailureResult = await this.TryGetSingle<FailedMessage>("/api/errors/", m => m.Id == ctx.DecommissionedEndpointUniqueMessageId && m.Status == FailedMessageStatus.Unresolved);
+                    var decomissionedFailureResult = await this.TryGetSingle<FailedMessageView>("/api/errors/", m => m.Id == ctx.DecommissionedEndpointUniqueMessageId && m.Status == FailedMessageStatus.Unresolved);
                     decomissionedFailure = decomissionedFailureResult;
-                    var successfullyRetriedResult = await this.TryGetSingle<FailedMessage>("/api/errors/", m => m.Id == ctx.MessageThatWillFailUniqueMessageId && m.Status == FailedMessageStatus.Resolved);
+                    var successfullyRetriedResult = await this.TryGetSingle<FailedMessageView>("/api/errors/", m => m.Id == ctx.MessageThatWillFailUniqueMessageId && m.Status == FailedMessageStatus.Resolved);
                     successfullyRetried = successfullyRetriedResult;
                     return decomissionedFailureResult && successfullyRetriedResult;
                 })

src/ServiceControl.Persistence/ExternalIntegrations/ExternalIntegrationDispatchRequest.cs

@@ -2,7 +2,7 @@ namespace ServiceControl.ExternalIntegrations
 {
     public class ExternalIntegrationDispatchRequest
     {
-        public required string Id { get; set; }
+        public string? Id { get; set; }
         public required object DispatchContext;
     }
 }

src/ServiceControl.Persistence/FailedMessage.cs

@@ -8,17 +8,12 @@ public class FailedMessage : IHaveStatus
     {
         public FailedMessage()
         {
-            // these ID fields *should* be marked as required
-            // but there seem to be some wire usages of this type for 
-            // deserialisation that omit the UniqueMessageId on output
-            Id = string.Empty;
-            UniqueMessageId = string.Empty;
             ProcessingAttempts = [];
             FailureGroups = [];
         }
 
-        public required string Id { get; set; }
-        public string UniqueMessageId { get; set; }
+        public string? Id { get; set; }
+        public required string UniqueMessageId { get; set; }
 
         public List<ProcessingAttempt> ProcessingAttempts { get; set; }
         public List<FailureGroup> FailureGroups { get; set; }