Implemented CLITypePrinter.VisitTemplateParameterSubstitutionType.

Should fix https://github.com/mono/CppSharp/issues/651.

src/Generator/Generators/CLI/CLITypePrinter.cs

@@ -285,7 +285,7 @@ namespace CppSharp.Generators.CLI
         public string VisitTemplateParameterSubstitutionType(
             TemplateParameterSubstitutionType param, TypeQualifiers quals)
         {
-            throw new NotImplementedException();
+            return param.Replacement.Visit(this);
         }
 
         public string VisitInjectedClassNameType(InjectedClassNameType injected, TypeQualifiers quals)