Draft: Engine: enable 3 digit pal sequence in OSD and Duke3D game text

Palettes may be defined from 0 to 251, but in OSD and Duke3D, the escape sequence "^#" only accepts two digits currently.

In the Build engine code, some instances where this is parsed already uses 3 digits. With this MR, all cases where the pal sequence is parsed now uses three digits, and existing engine strings have been adjusted accordingly to prevent swallowing characters or displaying the wrong color.

There is a low potential for breaking some mod quotes that used colored text, if these quotes happen to continue with another digit. Highly unlikely however.