Fix color fonts with DirectWrite backend

The logic to detect color fonts in the GDI font database was never
implemented in the DirectWrite database, causing emojis to look
monochrome. The patch moves this into the font engine itself instead,
along with the other initialization code.

Pick-to: 6.7
Fixes: QTBUG-122168
Change-Id: I6f5dad579bd987149e613b8071821aaf70a89bc2
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/gui/text/windows/qwindowsfontdatabase.cpp

@@ -1257,9 +1257,6 @@ QFontEngine *QWindowsFontDatabase::createEngine(const QFontDef &request, const Q
 
                     QFontDef fontDef = request;
                     fontDef.families = QStringList(QString::fromWCharArray(n));
-
-                    if (isColorFont)
-                        fedw->glyphFormat = QFontEngine::Format_ARGB;
                     fedw->initFontInfo(fontDef, dpi);
                     fe = fedw;
                 }

src/gui/text/windows/qwindowsfontenginedirectwrite.cpp

@@ -1033,6 +1033,10 @@ void QWindowsFontEngineDirectWrite::initFontInfo(const QFontDef &request,
             names->Release();
         }
 
+        // Color font
+        if (face3->GetPaletteEntryCount() > 0)
+            glyphFormat = QFontEngine::Format_ARGB;
+
         face3->Release();
     }
 #endif