Updated RunbookRetentionPeriod to support RetentionUnit (#937)

Introduces the Unit property as an enum to the RunbookRetentionPeriod model in Octopus.Client to match the server's contract.

Author: enf0rc3

source/Octopus.Client.Tests/PublicSurfaceAreaFixture.ThePublicSurfaceAreaShouldNotRegress..NETCore.approved.txt

@@ -5085,6 +5085,15 @@ Octopus.Client.Model
     .ctor()
     Int32 QuantityToKeep { get; set; }
     Boolean ShouldKeepForever { get; set; }
+    Octopus.Client.Model.RunbookRetentionUnit Unit { get; set; }
+  }
+  class RunbookRetentionUnit
+    IComparable
+    Octopus.TinyTypes.CaseInsensitiveStringTinyType
+  {
+    .ctor(String)
+    static Octopus.Client.Model.RunbookRetentionUnit Days { get; }
+    static Octopus.Client.Model.RunbookRetentionUnit Items { get; }
   }
   abstract class RunbookRun
   {

source/Octopus.Client.Tests/PublicSurfaceAreaFixture.ThePublicSurfaceAreaShouldNotRegress..NETFramework.approved.txt

@@ -5103,6 +5103,15 @@ Octopus.Client.Model
     .ctor()
     Int32 QuantityToKeep { get; set; }
     Boolean ShouldKeepForever { get; set; }
+    Octopus.Client.Model.RunbookRetentionUnit Unit { get; set; }
+  }
+  class RunbookRetentionUnit
+    IComparable
+    Octopus.TinyTypes.CaseInsensitiveStringTinyType
+  {
+    .ctor(String)
+    static Octopus.Client.Model.RunbookRetentionUnit Days { get; }
+    static Octopus.Client.Model.RunbookRetentionUnit Items { get; }
   }
   abstract class RunbookRun
   {

source/Octopus.Server.Client/Model/RunbookRetentionPeriod.cs

@@ -1,9 +1,10 @@
-namespace Octopus.Client.Model
+namespace Octopus.Client.Model;
+
+public class RunbookRetentionPeriod
 {
-    public class RunbookRetentionPeriod
-    {
-        public int QuantityToKeep { get; set; }
+    public int QuantityToKeep { get; set; }
+
+    public bool ShouldKeepForever { get; set; }
 
-        public bool ShouldKeepForever { get; set; }
-    }
+    public RunbookRetentionUnit Unit { get; set; } = RunbookRetentionUnit.Items;
 }

source/Octopus.Server.Client/Model/RunbookRetentionUnit.cs

@@ -0,0 +1,9 @@
+using Octopus.TinyTypes;
+
+namespace Octopus.Client.Model;
+
+public class RunbookRetentionUnit(string value) : CaseInsensitiveStringTinyType(value)
+{
+    public static RunbookRetentionUnit Days => new("Days");
+    public static RunbookRetentionUnit Items => new("Items");
+}