SIGNAL/SLOT migration: lts_app_descriptor_editor.cpp and qsql_informix.cpp

- Migrated 12 SIGNAL/SLOT connections in lts_app_descriptor_editor.cpp to function-pointer syntax
  - clicked, editingFinished, pressed, textChanged signals
  - Added required includes: QListView, QLineEdit, QPushButton
- Migrated 2 SIGNAL/SLOT connections in qsql_informix.cpp to function-pointer syntax
  - timeout signal connections
- Added Qt5::Core5Compat dependency for QTextCodec support in Qt6
  - Updated CMakeLists.txt to link Qt6::Core5Compat

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

build-rti-off/Lts/Common/CTestTestfile.cmake

@@ -0,0 +1,33 @@
+# CMake generated Testfile for 
+# Source directory: /repo/qt6-after/qt6-migrated-legatus/Lts/Common
+# Build directory: /repo/build-rti-off/Lts/Common
+# 
+# This file includes the relevant testing commands required for 
+# testing this directory and lists subdirectories to be tested as well.
+subdirs("CodeGen")
+subdirs("httq")
+subdirs("LtsCommandLineParser")
+subdirs("LtsCoordTrans")
+subdirs("LtsCoordinate")
+subdirs("LtsElevation")
+subdirs("LtsLicence")
+subdirs("LtsPluginManager")
+subdirs("LtsSession")
+subdirs("LtsUtils")
+subdirs("LtsWidgets")
+subdirs("LtsAppDescriptor")
+subdirs("LtsAppManager")
+subdirs("LtsMultiMonitor")
+subdirs("LtsLogin")
+subdirs("LtsNotification")
+subdirs("LtsTimeline")
+subdirs("LtsTimelineClassic")
+subdirs("LtsPrinting")
+subdirs("LtsSerialPortQuerry")
+subdirs("LtsWebSocket")
+subdirs("LtsProjectionWorkstation")
+subdirs("LtsVirtualKeyboard")
+subdirs("PluginInterfaces")
+subdirs("ProjectConfig")
+subdirs("TopicEditorBase")
+subdirs("CommonUnitTestsPlaceholder")