add `OwnerId` to threads

src/Discord.Net.Core/Entities/Channels/IThreadChannel.cs

@@ -74,6 +74,11 @@ namespace Discord
         /// </remarks>
         new DateTimeOffset CreatedAt { get; }
 
+        /// <summary>
+        ///     Gets the id of the creator of the thread.
+        /// </summary>
+        ulong OwnerId { get; }
+
         /// <summary>
         ///     Joins the current thread.
         /// </summary>

src/Discord.Net.Rest/Entities/Channels/RestThreadChannel.cs

@@ -40,6 +40,9 @@ namespace Discord.Rest
         /// <inheritdoc/>
         public IReadOnlyCollection<ulong> AppliedTags { get; private set; }
 
+        /// <inheritdoc/>
+        public ulong OwnerId { get; private set; }
+
         /// <inheritdoc cref="IThreadChannel.CreatedAt"/>
         public override DateTimeOffset CreatedAt { get; }
 
@@ -76,6 +79,8 @@ namespace Discord.Rest
                 IsLocked = model.ThreadMetadata.Value.Locked.GetValueOrDefault(false);
             }
 
+            OwnerId = model.OwnerId.GetValueOrDefault(0);
+
             MemberCount = model.MemberCount.GetValueOrDefault(0);
             MessageCount = model.MessageCount.GetValueOrDefault(0);
             Type = (ThreadType)model.Type;

src/Discord.Net.WebSocket/Entities/Channels/SocketThreadChannel.cs

@@ -95,6 +95,9 @@ namespace Discord.WebSocket
         /// <inheritdoc cref="IThreadChannel.CreatedAt"/>
         public override DateTimeOffset CreatedAt { get; }
 
+        /// <inheritdoc cref="IThreadChannel.OwnerId"/>
+        ulong IThreadChannel.OwnerId => _ownerId;
+
         /// <summary>
         ///     Gets a collection of cached users within this thread.
         /// </summary>