[FR] Add the LCD model in the About screen

[andrivet]

Since today, there at least two different models of the LCD screen for this printer, detect and report the model number (can help in case of a bug specific to a model).

[SureshotM6]

R0 on my DMT48270M043_02WT contains 0x00. Unfortunately, it is very likely that is not valid since that overlaps with a different LCD model in the manual. Could you see what your _05W returns, as it is not listed in the manual either? I added this code at the end of get_lcd_firmware_version(), which I can submit a pull request for if you get something other than 0x00:

String PrinterImpl::get_lcd_firmware_version()
{
    ...

    frame = ReadRegisterDataRequest(Register::R0, 1);
    frame.send();

    if(!response.receive(frame))
    {
        Log::error() << F("Receiving Frame (R0)") << Log::endl();
        return lcd_version;
    }

    response >> version;
    lcd_version << " " << hex_byte(version.byte);

    return lcd_version;
}

The code definitely works, as I am able to read other registers such as R1 as the correct values.

[andrivet]

Already made the test. Returns also 0

[andrivet]

In fact, R0 does not give the model number. It is the "screen mode" and is probably always zero. These screens are not DGUS but Mini DGUS and there are some differences.