Limit status message display taking multi-byte characters into account

[tcm0116]

This PR reverts the changes made in #6816 and implements my proposed solution in the comments for that PR.

To test this on my machine with a 20x4 LCD, I set the machine name to "MACHINE NAME ó" and set the language to "ca" (the 'ó' character is a two-byte Unicode charter). It would be a good idea of someone with a DOGM display could perform similar testing.

This first image shows the result with #6816 applied, and it can be seen that the status message is missing one character.

This image shows the change in #6816 reverted.

This image is with this PR applied.

For this image, I removed the special character from the machine name to verify the message is clipped properly with​ only single-byte charters in the string.

And finally, I set the machine name to a short value to show that messages less than LCD_WIDTH are displayed properly.

[tcm0116]

@Roxy-3D Since I know you have a DOGLCD, would you mind testing this if you have a chance?

[Roxy-3D]

I'll try to remember to do that... I have a very long print running right now, so it will be tomorrow before I can do that.

[thinkyhead]

The reason I limited the change only to the printing of the status message was to avoid adding any overhead to the lcd_print functions themselves, which are used to print just about everything on the screen. We recently did a heavy optimization to the LCD code, and I would like to continue to strip cycles. I suggest that if we want a function that takes a maxlength, we should add that as a new and separate function, and only use it in those instances where a string might potentially be too long (or if it needs charset_mapper).