Add BUILD_RTI conditionals for RTI/DDS dependent libraries

Systematic fix for BUILD_RTI conditional compilation:
- Lts/Common: Wrap all DDS-dependent libraries in IF(BUILD_RTI)
  - LtsAppManager, LtsCoordTrans, LtsCoordinate, LtsLogin
  - LtsMultiMonitor, LtsPluginManager, LtsPrinting
  - LtsProjectionWorkstation, LtsScriptTimeline, LtsSession
  - LtsTimelineClassic, LtsUtilsCore, LtsUtilsGui, LtsUtilsGuiDds
- Lts/DDS: Add BUILD_RTI guards to Core, DDSConnector, DdsUnitTests, FTC, FTS
- Lts/Plugins: Add BUILD_RTI guards to FilterManagement, OperatorManagement, SituationReplayManagement
- Lts/Proxies: Add BUILD_RTI guards to Buildings, CombatNetRadio, ComponentMonitor, GuezNasat, TrainingAreaBase, TrainingAreaBaseOC
- Lts/Services: Add BUILD_RTI guards to all 30+ service modules
- Z/nglwidgets: Add BUILD_RTI guards, fix Poppler Qt6 headers

Qt6 compatibility fixes:
- LtsCoordTrans: QOverload signal signature, QChar constructor
- LtsMultiMonitor: setMargin→setContentsMargins, remove deprecated HighQualityAntialiasing
- nglwidgets: Poppler Qt5→Qt6 header migration
- Add FindPopplerQt6.cmake for Qt6 Poppler detection

Part of Qt5→Qt6 migration with RTI DDS support.

qt6-after/qt6-migrated-legatus/Lts/Common/LtsScriptTimeline/CMakeLists.txt

@@ -55,6 +55,9 @@ SET(LtsScriptTimeline_UICS
 
 NGL_WRAP_UI(LtsScriptTimeline_SRCS ${LtsScriptTimeline_UICS})
 
+SET(CMAKE_AUTOUIC_SEARCH_PATHS ${CMAKE_CURRENT_SOURCE_DIR}/Ui)
+
+IF(BUILD_RTI)
 NGL_ADD_LIBRARY2(WS LtsScriptTimeline SHARED ${LtsScriptTimeline_SRCS} ${LtsScriptTimeline_UICS})
 
 NGL_TARGET_INCLUDE_DIRECTORIES(LtsScriptTimeline
@@ -68,3 +71,4 @@ NGL_TARGET_LINK_LIBRARIES(LtsScriptTimeline
   LtsWidgets
   LtsSessionData
 )
+ENDIF(BUILD_RTI)