Reworked ISortBy interface

Author: michaelstaib

src/HotChocolate/Primitives/src/Primitives.Data/ISortBy.cs

@@ -13,7 +13,7 @@ public interface ISortBy<TEntity>
     /// <summary>
     /// Gets the field on which the sort operation is applied.
     /// </summary>
-    Expression KeySelector { get; }
+    LambdaExpression KeySelector { get; }
 
     /// <summary>
     /// Gets the sort direction.

src/HotChocolate/Primitives/src/Primitives.Data/SortBy.cs

@@ -35,7 +35,7 @@ public SortBy(Expression<Func<TEntity, TValue>> keySelector, bool ascending = tr
     /// </summary>
     public Expression<Func<TEntity, TValue>> KeySelector { get; init; }
 
-    Expression ISortBy<TEntity>.KeySelector => KeySelector;
+    LambdaExpression ISortBy<TEntity>.KeySelector => KeySelector;
 
     /// <summary>
     /// Gets the sort direction.