fix: change the behavior of printf in string op.

- add compiler hint for checking the arguments of printf.
- change the return value of printf. from std::expected to normal value. use C++ exception to indicate error.
	* the error of printf usually caused by programmer. so it can be found when testing program.
	* so i use std::logic_error to indicate this and programmer should fix this before releasing program.
- change the use of encoding convertion. for those cases that convertion must be safe, we unwrap it directly.

src/yycc/carton/wcwidth.cpp

@@ -468,11 +468,8 @@ namespace yycc::carton::wcwidth {
     }
 
     Result<size_t> wcswidth(const std::u8string_view& rhs) {
-        // Cast encoding
-        auto u32str = ENC::to_utf32(rhs);
-        if (!u32str.has_value()) return std::unexpected(Error::BadEncoding);
-        // Call underlying function
-        return wcswidth(u32str.value());
+        // Cast encoding and call underlying function
+        return wcswidth(ENC::to_utf32(rhs).value());
     }
 
 } // namespace yycc::carton::wcwidth