fix(baseN, hex): const string& -> string_view

include/base/hex.hpp

@@ -1,15 +1,16 @@
 #pragma once
 
 #include <cstdint>
+#include <span>
 #include <string>
 #include <vector>
 
 namespace hex
 {
     bool isValid(const char *str) noexcept;
-    bool isValid(const std::string &str) noexcept;
+    bool isValid(std::string_view str) noexcept;
     void encode(const uint8_t *data, uint64_t data_size, char *str) noexcept;
-    std::string encode(const std::vector<uint8_t> &data) noexcept;
+    std::string encode(std::span<const uint8_t> data) noexcept;
     void decode(const char *str, uint8_t *data, uint64_t data_size);
-    std::vector<uint8_t> decode(const std::string &str);
+    std::vector<uint8_t> decode(std::string_view str);
 }