`SELECT ... WHERE match(key, '^prefix...')`
should use index similarly to
`SELECT ... WHERE key LIKE 'prefix%'`
{
    String fixed_prefix;
    const char * pos = like_pattern.data();
    const char * end = pos + like_pattern.size();
    while (pos < end)
    {
        switch (*pos)
        {
            case '%':
                [[fallthrough]];
            case '_':
                return fixed_prefix;
            case '\\':
                ++pos;
                if (pos == end)
                    break;
                [[fallthrough]];
            default:
                fixed_prefix += *pos;
                break;
        }
        ++pos;
    }
    return fixed_prefix;
}
/** For a given string, get a minimum string that is strictly greater than all strings with this prefix,
  *  or return an empty string if there are no such strings.
  */
static String firstStringThatIsGreaterThanAllStringsWithPrefix(const String & prefix)