set INSTALL_TO_SITEPACKAGES to ON by default

and add some modules to the freecad-namespace (freecad.part, freecad.partdesign, freecad.sketcher)

cMake/FreeCAD_Helpers/InitializeFreeCADBuildOptions.cmake

@@ -14,7 +14,7 @@ macro(InitializeFreeCADBuildOptions)
     option(FREECAD_BUILD_DEBIAN "Prepare for a build of a Debian package" OFF)
     option(BUILD_WITH_CONDA "Set ON if you build FreeCAD with conda" OFF)
     option(BUILD_DYNAMIC_LINK_PYTHON "If OFF extension-modules do not link against python-libraries" ON)
-    option(INSTALL_TO_SITEPACKAGES "If ON the freecad root namespace (python) is installed into python's site-packages" OFF)
+    option(INSTALL_TO_SITEPACKAGES "If ON the freecad root namespace (python) is installed into python's site-packages" ON)
     option(OCCT_CMAKE_FALLBACK "disable usage of occt-config files" OFF)
     if (WIN32 OR APPLE)
         option(FREECAD_USE_QT_FILEDIALOG "Use Qt's file dialog instead of the native one." OFF)

src/Ext/freecad/CMakeLists.txt

@@ -38,6 +38,9 @@ endif()
 INSTALL(
     FILES
         ${NAMESPACE_INIT}
+        part.py
+        partdesign.py
+        sketcher.py
         project_utility.py
         UiTools.py
         utils.py

src/Ext/freecad/part.py

@@ -0,0 +1 @@
+from Part import *

src/Ext/freecad/partdesign.py

@@ -0,0 +1 @@
+from PartDesign import *

src/Ext/freecad/sketcher.py

@@ -0,0 +1 @@
+from Sketcher import *