Rebase and remove polyfill

src/Discord.Net.Commands/Utilities/ValueTuplePolyfill.cs

@@ -1,24 +0,0 @@
-#if !NetStandard20
-
-namespace System
-{
-    internal struct ValueTuple<T1, T2>
-    {
-        public T1 Item1;
-        public T2 Item2;
-    }
-}
-
-namespace System.Runtime.CompilerServices
-{
-    using System.Collections.Generic;
-    internal class TupleElementNamesAttribute : Attribute
-    {
-        public IList<string> TransformNames { get; }
-        public TupleElementNamesAttribute(string[] transformNames)
-        {
-            TransformNames = transformNames;
-        }
-    }
-}
-#endif