[SYCL] Make sycl::kernel_id owns MName instead of using string_view (#18696)

In 8a5462d for preview the type was changed to string_view, but in some
scenario memory for kernel name is released before kernel_id is used. In
common case kernel_id_impl is created from ProgramManager::addImages(),
i.e. not on hot path.

Author: Alexandr-Konovalov

sycl/source/detail/kernel_id_impl.hpp

@@ -38,7 +38,7 @@ class kernel_id_impl {
   const char *get_name() { return MName.data(); }
 
 private:
-  KernelNameStrT MName;
+  std::string MName;
 };
 
 } // namespace detail