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/roundpopupwidget.cpp

@@ -31,7 +31,6 @@ void RoundPopupWidget::initUI()
     setMaskColor(DBlurEffectWidget::LightColor);
     setMaskAlpha(BlurMaskAlpha);
     m_mainLayout->setMargin(0);
-    m_mainLayout->setSpacing(0);
     m_mainLayout->setContentsMargins(MARGIN, MARGIN, MARGIN, MARGIN);
     setLayout(m_mainLayout);
 }

src/widgets/useritemdelegate.cpp

@@ -157,7 +157,7 @@ void UserItemDelegate::drawNameAndType(QPainter *painter, const UserItemData &us
     QString displayNameText = elidedText(userData.displayName, textAreaWidth + 1, font.pixelSize(), true);
 
     QTextOption qTextOption;
-    qTextOption.setAlignment(Qt::AlignmentFlag::AlignVCenter | Qt::AlignmentFlag::AlignLeft);
+    qTextOption.setAlignment(Qt::AlignmentFlag::AlignVCenter);
     painter->drawText(displayNameRect, displayNameText, qTextOption);
 
     QFont typeFont = DFontSizeManager::instance()->t8();