Bugfix: The print safely functions are not fully UTF-8 aware.

Bugfix: The print safely functions are not fully UTF-8 aware.

The f_print_character_safely_get() can only handle a single byte.
This makes it impossible to be UTF-8 aware.

Provide a new function f_print_safely_get() that accepts a string and a max width.
This string is intended to represent a single character, but can be multi-byte based on max width.
This function checks to see if the character is invalid or a control character, in which case it is replaced.