CMake: Rename add_qt_gui_executable to qt_add_executable

Also adjust pro2cmake to use the new qt_add_executable name
instead of add_qt_gui_executable.

No compatibility functions provided this time, so we'll need to follow
through all repos and regenerate all examples.

Two reasons for not providing compaitibility functions:
1) We don't intend add_qt_gui_executable to be public API
2) A previous case with qtquickcontrols2 and qttools pointed out that
making top-level builds work with cross-compatibility API is not
simple. So just go ahead and regenerate everything.

Task-number: QTBUG-87661
Change-Id: I2f228827b786ae03bf7e1bf3908ea02a8794ed52
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

src/corelib/Qt6CoreMacros.cmake

@@ -426,7 +426,7 @@ set(_Qt6_COMPONENT_PATH "${CMAKE_CURRENT_LIST_DIR}/..")
 # It's signature and behavior might change.
 #
 # Wrapper function that adds an executable with some Qt specific behavior.
-function(add_qt_gui_executable target)
+function(qt6_add_executable target)
     if(ANDROID)
         add_library("${target}" MODULE ${ARGN})
         # On our qmake builds we do don't compile the executables with
@@ -456,6 +456,13 @@ function(add_qt_gui_executable target)
     endif()
 endfunction()
 
+if(NOT QT_NO_CREATE_VERSIONLESS_FUNCTIONS)
+    function(qt_add_executable)
+        qt6_add_executable(${ARGV})
+    endfunction()
+endif()
+
+
 function(_qt_get_plugin_name_with_version target out_var)
     string(REGEX REPLACE "^Qt::(.+)" "Qt${QT_DEFAULT_MAJOR_VERSION}::\\1"
            qt_plugin_with_version "${target}")

util/cmake/pro2cmake.py

@@ -3719,7 +3719,7 @@ def write_example(
             add_target += f"target_sources({binary_name} PRIVATE"
 
     else:
-        add_target = f'add_{"qt_gui_" if gui else ""}executable({binary_name}'
+        add_target = f'qt_add_executable({binary_name}'
 
     write_all_source_file_lists(cm_fh, scope, add_target, indent=0)
     cm_fh.write(")\n")