Engine: Initialize a FhirEvalutionContext via ctor

Static method FhirEvaluationContext.CreateDefault() is marked as
obsolete initialize a FhirEvalutionContext via the ctor instead.

src/Spark.Engine/Service/FhirServiceExtensions/ElementNavFhirExtensionsNew.cs

@@ -34,7 +34,7 @@ public static IEnumerable<Base> SelectNew(
         FhirEvaluationContext ctx = null)
     {
         var inputNav = input.ToTypedElement();
-        var result = inputNav.Select(expression, ctx ?? FhirEvaluationContext.CreateDefault());
+        var result = inputNav.Select(expression, ctx ?? new FhirEvaluationContext());
         return result.ToFhirValues();
     }
 
@@ -64,4 +64,4 @@ public static IEnumerable<Base> ToFhirValues(this IEnumerable<ITypedElement> res
             };
         });
     }
-}
+}