fix: 修复字体字号为20的时候锁屏界面切换用户列表文字被遮挡的问题

监听字体字号改变信号，实时更新列表宽度

Log:
Bug: linuxdeepin/developer-center#8873
Influence: 切换用户列表文字展示

src/widgets/useritemdelegate.cpp

@@ -184,7 +184,9 @@ void UserItemDelegate::drawNameAndType(QPainter *painter, const UserItemData &us
     // 绘制userType, +1个像素为了避免字体大小不一样，绘制中心位置不一致
     int userTypeLeft = userData.name.isEmpty() ? displayNameRect.left() : displayNameRect.left() + nameWidth + itemSpacing;
     QRect userTypeRect = QRect(userTypeLeft, displayNameRect.bottom() + LABEL_SPACE + 1, userTypeAreaWidth + 1, userTypeHeight());
+    painter->setOpacity(0.7);
     painter->drawText(userTypeRect, userData.userStrType, qTextOption);
+    painter->setOpacity(1);
 }
 
 void UserItemDelegate::drawCheckedState(QPainter *painter, const QRect &rect) const