[Fonts] Keep CardText call sites on the app font and fix px sizes

- CardText's unset fallback is qApp->font() again: only the three counter
  painters (paintNumberEllipse, GeneralCounter, PlayerCounter) were Serif
  before the role existed, and they now ask for it through
  ThemeManager::cardTextFont(). Card names, player names, counters, the
  overlay, the Archidekt and EDHREC labels and the completer delegate keep the
  app font they used before.
- Use setPixelSize for the EDHREC card name (20px) and commander name (28px)
  and details (16px) sizes: the stylesheets said px, and setPointSize made
  them about a third larger.

cockatrice/src/game_graphics/board/counter_general.cpp

@@ -42,7 +42,7 @@ void GeneralCounter::paint(QPainter *painter, const QStyleOptionGraphicsItem * /
     painter->drawPixmap(QPoint(0, 0), pixmap);
 
     if (value) {
-        QFont f = themeManager->appFont(AppFont::CardText);
+        QFont f = themeManager->cardTextFont();
         f.setPixelSize(qMax((int)(radius * scaleFactor), 10));
         f.setWeight(QFont::Bold);
         painter->setPen(Qt::black);