This function was written for already validated UTF-8 but not for text that can be mixed with ISO-8859-1.
To handle that properly it needs to do a bit more validation to avoid mangling its output and instead reject invalid input.
This was broken by several small unicode-incompatible code fragments.
This commit also removes the input limit for the player name and the savegame description. With multibyte encoding, limiting them to a fixed length did not work right.
Currently these will just overflow the fields if the text becomes too long, this needs some additional work.
This also necessitated some character remapping in the console font to move the Windows-1252 extra characters to their proper Unicode code points.
# Conflicts:
# src/CMakeLists.txt
# src/posix/sdl/i_input.cpp
# src/scripting/backend/codegen.cpp
# src/v_font.cpp
# Conflicts:
# src/c_console.cpp
