Move wordwrapping functions and len to Font.cpp/font:: namespace

The following functions were moved directly:
- next_wrap
- next_wrap_s
- string_wordwrap
- string_wordwrap_balanced
- string_unwordwrap

These ones will probably still need get a flags argument, except for
string_unwordwrap (since they need to know what font we're talking
about.

The implementation of graphics.len has also been moved to Font.cpp,
but graphics.len still exists for now and is deprecated.

desktop_version/src/LocalizationMaint.cpp

@@ -6,6 +6,7 @@
 
 #include "Alloc.h"
 #include "FileSystemUtils.h"
+#include "Font.h"
 #include "Graphics.h"
 #include "Script.h"
 #include "Vlogging.h"
@@ -198,7 +199,7 @@ static void sync_lang_file(const std::string& langcode)
                 }
 
                 size_t alloc_len;
-                const std::string eng_unwrapped = graphics.string_unwordwrap(eng);
+                const std::string eng_unwrapped = font::string_unwordwrap(eng);
                 char* eng_prefixed = add_disambiguator(subElem->UnsignedAttribute("case", 1), eng_unwrapped.c_str(), &alloc_len);
                 if (eng_prefixed == NULL)
                 {