Replace Padder CRTP base with a concept.

Chaos/Padding/PadderIso7816.hpp

@@ -12,7 +12,7 @@
 namespace Chaos::Padding
 {
 
-class PadderIso7816 : public Padder<PadderIso7816>
+class PadderIso7816
 {
 public:
     template<typename OutputIt>
@@ -82,6 +82,8 @@ private:
     using Branchless = Service::Branchless;
 };
 
+static_assert(Padder<PadderIso7816>);
+
 } // namespace Chaos::Padding
 
 #endif // CHAOS_PADDING_PADDERISO7816_HPP