[ox/std] Add const char *toStr(const ox::Error&)

(synced from 53939a28c6)

src/ox/std/error.hpp

@@ -75,6 +75,11 @@ struct [[nodiscard]] Error {
 
 };
 
+[[nodiscard]]
+constexpr auto toStr(const Error &err) noexcept {
+	return err.msg;
+}
+
 struct Exception: public std::exception {
 	const char *msg = nullptr;
 	const char *file = nullptr;