Qt6 migration: Fix BUILD_RTI=OFF build errors in TrainingAreaBase

- training_area_telegrams.cpp: Fixed QJsonObject initializer syntax (Qt6 requires {{}} not ({}))
- training_area_telegrams.cpp: Fixed fromJson() methods to access m_* members directly
- training_area_telegrams.cpp: Fixed brace mismatches in multiple toJson() methods
- training_area_telegrams.h: Changed Header struct to public members for consistency
- tx_mixin.cpp: Fixed getEquipmentNumber() template for direct member access
- lts_coordinate.cpp: Added missing #include <iomanip>
- MIGRATION_STATUS.md: Added migration progress tracking document

C++17 constraint enforced due to RTI Connext DDS 7.7.0 incompatibility with C++20+

Build status: BUILD_RTI=OFF successful (0 errors, warnings only)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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

@@ -10,7 +10,7 @@
 #include <LtsSession/lts_session.h>
 #include <LtsUtils/LtsUtilsGui/LtsUtilsGuiDds/request_helper.h>
 #include <PluginInterfaces/gui_plugin_interface.h>
-#include <QTreeView>
+#include <QtWidgets/QTreeView>
 
 namespace AudioVideoManagement
 {

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

@@ -3,9 +3,9 @@
 #include "avm_mvs_dialog.h"
 
 #include <FileManagement/flm_translation.h>
-#include <QJsonArray>
-#include <QJsonDocument>
-#include <QJsonObject>
+#include <QtCore/QJsonArray>
+#include <QtCore/QJsonDocument>
+#include <QtCore/QJsonObject>
 
 namespace AudioVideoManagement
 {

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

@@ -8,7 +8,7 @@
 #include <AudioVideoManagement/avm_dtc.h>
 #include <PluginInterfaces/gui_plugin_interface.h>
 #include <Plugins/AudioVideoManagement/avm_mvs_video_team_gui_plugin_interface.h>
-#include <QButtonGroup>
+#include <QtWidgets/QButtonGroup>
 
 namespace AudioVideoManagement
 {

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

@@ -9,10 +9,10 @@
 #include <LtsSession/lts_session.h>
 #include <Services/AudioVideoManagement/avm_operator_rights.h>
 #include <LtsUtilsSettings/settings.h>
-#include <QApplication>
+#include <QtWidgets/QApplication>
 #include <QDesktopWidget>
-#include <QProcess>
-#include <QScreen>
+#include <QtCore/QProcess>
+#include <QtGui/QScreen>
 
 namespace AudioVideoManagement
 {

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

@@ -1,9 +1,9 @@
 #include "receiverelement.h"
 #include "ui_receiverelement.h"
 
-#include <QPainter>
+#include <QtGui/QPainter>
 #include <QStyleOption>
-#include <QStyle>
+#include <QtWidgets/QStyle>
 
 ReceiverElement::ReceiverElement(QWidget *parent)
   : QWidget(parent)

qt6-after/qt6-migrated-legatus/Lts/Plugins/AudioVideoManagement/Gui/MobileVideoSystem/receiverelement.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <QRadioButton>
+#include <QtWidgets/QRadioButton>
 #include <AudioVideoManagement/avm.hpp>
 
 namespace Ui

qt6-after/qt6-migrated-legatus/Lts/Plugins/AudioVideoManagement/Gui/MobileVideoSystem/receiveritem.h

@@ -1,6 +1,6 @@
 #pragma once
-#include <QGroupBox>
-#include <QTimer>
+#include <QtWidgets/QGroupBox>
+#include <QtCore/QTimer>
 
 namespace Ui
 {