QDesktopWidget → QScreen: Complete migration in AVM and TetraIF modules

- avm_mvs_video_team_gui_plugin.cpp: QApplication::desktop() → QGuiApplication::primaryScreen()
- LogViewTelegramDialog.cpp: QApplication::desktop() → QGuiApplication::primaryScreen()
- Added QGuiApplication includes where needed
- Removed duplicate QScreen include

This completes the QDesktopWidget API migration across all modules.
QApplication::desktop() is deprecated in Qt5 and removed in Qt6.
Replacement: QGuiApplication::primaryScreen()->geometry() or availableGeometry().

Refs: Qt6 migration, C++17 constraint due to RTI Connext DDS 7.7.0 incompatibility

qt6-after/qt6-migrated-legatus/Lts/Plugins/AudioVideoManagement/Gui/MobileVideoSystem/avm_mvs_video_team_gui_plugin.cpp

@@ -11,8 +11,8 @@
 #include <LtsUtilsSettings/settings.h>
 #include <QtWidgets/QApplication>
 #include <QtGui/QScreen>
+#include <QtGui/QGuiApplication>
 #include <QtCore/QProcess>
-#include <QtGui/QScreen>
 
 namespace AudioVideoManagement
 {
@@ -116,7 +116,7 @@ LtsWidgets::LtsDialog *InterfaceImpl::onMvsRemoteDesktop(const QString &rdesktop
   LtsUtils::ProjectSettings *ps = LtsUtils::ProjectSettings::getInstance();
   const QString username = ps->value(QStringLiteral("avm"), QStringLiteral("mvsUser")).toString();
   const QString password = ps->value(QStringLiteral("avm"), QStringLiteral("mvsPassword")).toString();
-  QSize s = QApplication::desktop()->screenGeometry(parent).size();
+  QSize s = QGuiApplication::primaryScreen()->geometry().size();
   if (s.isEmpty())
     s = QSize(1920, 1080);
   s = s * 7 / 8;