API: improve code deduplication

[evgenykor]

No description provided.

[guycipher]

static void inline err_handler(tidesdb_err_t *err)
{
    if (err)
    {
        std::string error_message = err->message;
        const int error_code = err->code;
        tidesdb_err_free(err);
        throw std::runtime_error("Error " + std::to_string(error_code) + ": " + error_message);
    }
}

One question @evgenykor aren't you freeing the error? I'm not sure if we are copying the message, usually you copy the char array, also the const is redundant in such a local method no? Do let me know thoughts. I like the idea. I just think you're freeing the message by accident, I may be wrong though.

[evgenykor]

No, std::string error_message contructor will do deep copy of message so it is fine. We also have a negative test in CI

    catch (const std::runtime_error& e)
    {
        EXPECT_STREQ(e.what(), "Error 22: Key not found.\n");
    }

this would have a an issue otherwise accessing e.what()

Of course I am not freeing it by accident - we do need to free error since you allocate memory for it (if the error occurs)

And lastly code was like this even before my PR :) this just deduplication work

[evgenykor]

argument about int error_code is valid but I played too much with these Rust / Zig toys to have bias / schizofrenia of making all the world const

[guycipher]

I agree with the test. I had a feeling about the deep copy I just wanted to be sure. Too much C on my end.

Great work as always! @evgenykor