PostScript / PDF font embedding fails on Mac 64-bit due to unimplemented methods in QCoreTextFontEngine

Font embedding in PostScript and PDF fails in the CoreText implementation on the Mac due to a number of unimplemented methods in QCoreTextFontEngine.

1. QCoreTextFontEngine::faceId returns a dummy FaceId structure with no filename in. This is tested in QPdfBaseEnginePrivate::drawTextItem, which falls back to writing the characters as curves rather than embedding the font if no faceId could be found.

2. QCoreTextFontEngine::getUnscaledGlyph is completely unimplemented.

3. QCoreTextFontEngine has no override for QFontEngine::properties(), which means that embedded fonts would be given the wrong name (the base class implementation just uses the family name with style information appended, rather than calling a system API to get the real PostScript name).

4. QCoreTextFontEngine::stringToCMap is completely unimplemented. (Note that the equivalents in QCoreTextFontEngineMulti are implemented, but glyph naming in EPS export uses the former.)

This is related to 10089 which is a Windows-specific failure of font embedding in PS/PDF. The test case attached to that bug applies to this one too.