feat: add disableMarkCompletedWhenConfirmed (#946)

* Add `DisableMarkCompletedWhenConfirmed` flag to SyncAdapterSettings

* Format

Author: Fargekritt

src/Storage.Interface/Models/SyncAdapterSettings.cs

@@ -67,6 +67,13 @@ public class SyncAdapterSettings
         [DefaultValue(false)]
         public bool DisableSyncStatus { get; set; }
 
+        /// <summary>
+        /// Gets or sets the flag controlling whether the sync adapter should set status to completed when confirmed.
+        /// </summary>
+        [JsonProperty(PropertyName = "disableMarkCompletedWhenConfirmed")]
+        [DefaultValue(false)]
+        public bool DisableMarkCompletedWhenConfirmed { get; set; }
+
         /// <summary>
         /// Gets or sets the flag controlling whether the sync adapter should disable synchronizing (overwrite) the title.
         /// </summary>