Issue 4876/1: Add fontname replacing function for CFF (OTF/OTC) fonts

Issue 4876/1: Add fontname replacing function for CFF (OTF/OTC) fonts

For CFF (OTF/OTC) fonts,
FT_Get_Postscript_Name ()
in FreeType 2.6+ gets the name in 'name' table.
However, we want the name in 'CFF' table instead of in 'name' table
because output postscript file is embedded only 'CFF' table of the font.

They are inconsistent for some OpenType/CFF Collection fonts (OTC).

This function can get the name in 'CFF' table.

TODO: Check conflicts between fonts which have same name in 'CFF' table
but different name in 'name' table.