Clean up conv_traits.hpp (#3354)

When I asked for a description of operators that didn't have ConvTraits, I was getting very long confusing errors about ConvTraits not being defined. Now we get specific errors explaining which concepts are violated, making it easier to know which code to generalize or update.

* Add concepts to conv_traits.hpp to get better error message.
* Put the correct requires clauses in the right places to get descriptive error messages.
* General cleanup of functions in conv_traits.hpp to make functions easier to read.

Author: shumway

experimental/builder/include/ck_tile/builder/reflect/conv_description.hpp

@@ -251,14 +251,10 @@ class ConvDescription : public Description
 };
 } // namespace conv
 
-/// @brief Helper concept to detect if a type has ConvTraits specialization
-template <typename T>
-concept HasConvTraits = requires { typename conv::ConvTraits<T>; };
-
 /// @brief Factory function to create ConvDescription from a convolution instance type
-/// @tparam Instance The convolution instance type (must have InstanceTraits specialization)
+/// @tparam Instance The convolution instance type (must have ConvTraits specialization)
 /// @return A ConvDescription object populated with the instance's configuration details
-template <HasConvTraits Instance>
+template <conv::HasConvTraits Instance>
 conv::ConvDescription describe()
 {
     using Traits = conv::ConvTraits<Instance>;