Add Arabic ligature support

Montassar prepared a list of all the ligatures that needed to be
supported, which was a simple A+B->C table, so that one was not too
difficult either!

desktop_version/src/Font.cpp

@@ -1200,6 +1200,11 @@ int len(const uint32_t flags, const char* text)
 {
     PrintFlags pf = decode_print_flags(flags);
 
+    if (bidi_should_transform(text))
+    {
+        text = bidi_transform(text);
+    }
+
     int text_len = 0;
     uint32_t codepoint;
     while ((codepoint = UTF8_next(&text)))