Made available compilation on windows with msys2

The aim of this commit is to easily build qelectrotech under windows
with qt6/cmake and the package tool MSYS2.

-Update some cmake file.
-Remove Git submodule for pugixml and single application
-Use cmake find_package for pugi xml
-Use cmake fetchContent for single application.
-Use cmake find_package for KCoreAddons and KWidgetsAddons.
-Minor change for pugi xml
-Minor change on ProjectPrintWindow class to compatible with Qt6 API.

cmake/fetch_kdeaddons.cmake

@@ -1,4 +1,4 @@
-# Copyright 2006 The QElectroTech Team
+# Copyright 2006-2026 The QElectroTech Team
 # This file is part of QElectroTech.
 #
 # QElectroTech is free software: you can redistribute it and/or modify
@@ -14,25 +14,22 @@
 # You should have received a copy of the GNU General Public License
 # along with QElectroTech. If not, see <http://www.gnu.org/licenses/>.
 
-message(STATUS "fetch_kdeaddons")
-
-if(BUILD_WITH_KF6)
-  option(BUILD_KF6 "Build KF6 libraries, use system ones otherwise" OFF)
+option(BUILD_KF6 "Build KF6 libraries, use system ones otherwise" OFF)
+if(BUILD_KF6)
   block(PROPAGATE KF6_GIT_TAG)
-  set(BUILD_TESTING OFF)
-  set(KDE_SKIP_TEST_SETTINGS ON)
-  set(BUILD_DESIGNERPLUGIN OFF)
-  set(KCOREADDONS_USE_QML OFF)
-  set(BUILD_QCH OFF)
-  set(BUILD_SHARED_LIBS OFF)
-  find_package(ECM 6.8.0 REQUIRED NO_MODULE)
-  list(APPEND CMAKE_MODULE_PATH ${ECM_MODULE_PATH})
+    message(STATUS " - fetch_kdeaddons")
+    set(KDE_SKIP_TEST_SETTINGS ON)
+    set(KCOREADDONS_USE_QML OFF)
+    set(KWIDGETSADDONS_USE_QML OFF)
+    set(BUILD_TESTING OFF)
+    set(BUILD_DESIGNERPLUGIN OFF)
+    set(BUILD_QCH OFF)
+    set(BUILD_SHARED_LIBS OFF)
 
-  if(BUILD_KF6)
     Include(FetchContent)
 
     if(NOT DEFINED KF6_GIT_TAG)
-      set(KF6_GIT_TAG v6.8.0)
+      set(KF6_GIT_TAG v6.22.0)
     endif()
 
     FetchContent_Declare(
@@ -40,21 +37,19 @@ if(BUILD_WITH_KF6)
       GIT_REPOSITORY https://invent.kde.org/frameworks/kcoreaddons.git
       GIT_TAG        ${KF6_GIT_TAG})
     FetchContent_MakeAvailable(kcoreaddons)
-    get_target_property(kca_version KF6::CoreAddons VERSION)
 
-  else()
-    find_package(KF6CoreAddons REQUIRED)
-    set(kca_version ${KF6CoreAddons_VERSION})
-  endif()
-
-  get_target_property(kwa_type KF6::CoreAddons TYPE)
-
-  message(NOTICE "ecm version            : " ${ECM_VERSION})
-  message(NOTICE "kcoreaddons library    : " ${kca_type})
-  message(NOTICE "kcoreaddons version    : " ${kca_version})
+    FetchContent_Declare(
+      kwidgetsaddons
+      GIT_REPOSITORY https://invent.kde.org/frameworks/kwidgetsaddons.git
+      GIT_TAG        ${KF6_GIT_TAG})
+    FetchContent_MakeAvailable(kwidgetsaddons)
   endblock()
-
-  set(KF6_PRIVATE_LIBRARIES
-    KF6::CoreAddons
-    )
+else()
+  find_package(KF6CoreAddons REQUIRED)
+  find_package(KF6WidgetsAddons REQUIRED)
 endif()
+
+set(KF6_PRIVATE_LIBRARIES
+  KF6::CoreAddons
+  KF6::WidgetsAddons
+)