Pack.cmake: correct and unify the name of the BA installer on all platforms

The installer name is
<Project-Name>-<Project-Version>-python<Python-Version>-<architecture>
e.g., "BornAgain-20.0-python3.11-linux_x64" on Debian or
"BornAgain-20.0-python3.9-mac_arm.dmg" on MacOS-M1.

Added a CPack stage 'FixPackage' to adjust the installers (for MacOS and Linux).

cmake/BornAgain/Pack.cmake

@@ -12,6 +12,9 @@ set(CPACK_PACKAGE_RELOCATABLE True)
 set(CPACK_SOURCE_PACKAGE_FILE_NAME ${CMAKE_PROJECT_NAME}-${CMAKE_PROJECT_VERSION})
 set(CPACK_PACKAGE_INSTALL_DIRECTORY ${CPACK_SOURCE_PACKAGE_FILE_NAME})
 
+set(SELECTED_PYTHON_VERSION "python${Python3_VERSION_MAJOR}.${Python3_VERSION_MINOR}")
+set(_pkgname ${CPACK_SOURCE_PACKAGE_FILE_NAME}-${SELECTED_PYTHON_VERSION}-${BA_ARCHITECTURE})
+
 if(WIN32)
     include(BornAgain/PackWindows)
 elseif(APPLE)
@@ -24,9 +27,16 @@ elseif(UNIX)
     include(BornAgain/PackSource)
 endif()
 
+set(CPACK_PACKAGE_FILE_NAME ${_pkgname})
+
+# NOTE: The 'Unspecified' component is a _default_ component of CPack needed to finalize
+# the installer. It must be at the end of all other components.
+set(CPACK_COMPONENTS_ALL Libraries Headers Examples Applications Runtime Unspecified)
+
 include(CPack)
 
-set(CPACK_COMPONENTS_ALL Libraries Headers Examples Applications Runtime)
+# reset package name (CPack bug: the original value is overwritten by CPack module)
+set(CPACK_PACKAGE_FILE_NAME ${_pkgname})
 
 message(STATUS "Installer name: ${CPACK_PACKAGE_FILE_NAME}")
 message(STATUS "Source package name: ${CPACK_SOURCE_PACKAGE_FILE_NAME}")

cmake/BornAgain/PackMacOS.cmake

 # BornAgain Mac packaging
 
-set(SELECTED_PYTHON_VERSION "python${Python3_VERSION_MAJOR}.${Python3_VERSION_MINOR}")
-
-set(CPACK_PACKAGE_FILE_NAME
-    "${CMAKE_PROJECT_NAME}-${CMAKE_PROJECT_VERSION}-${SELECTED_PYTHON_VERSION}-${BA_ARCHITECTURE}")
-
 set(CPACK_BINARY_DRAGNDROP ON)
 set(CPACK_GENERATOR "DragNDrop")

cmake/BornAgain/PackWindows.cmake

 # BornAgain Windows packaging
 
-set(SELECTED_PYTHON_VERSION "python${Python3_VERSION_MAJOR}.${Python3_VERSION_MINOR}")
-
-set(CPACK_PACKAGE_FILE_NAME
-    "${CMAKE_PROJECT_NAME}-${CMAKE_PROJECT_VERSION}-${SELECTED_PYTHON_VERSION}-${BA_ARCHITECTURE}")
-
 set(CPACK_GENERATOR "NSIS")
 
 set(CPACK_NSIS_INSTALL_ROOT "C:")
@@ -12,7 +7,6 @@ set(CPACK_NSIS_ENABLE_UNINSTALL_BEFORE_INSTALL ON)
 
 set(CPACK_NSIS_MENU_LINKS "bin\\\\BornAgain.exe" "BornAgain")
 
-
 set(CPACK_PACKAGE_ICON "${CMAKE_CURRENT_SOURCE_DIR}/GUI\\\\images\\\\BornAgain.ico" )
 set(CPACK_NSIS_MUI_ICON "${CMAKE_CURRENT_SOURCE_DIR}/GUI\\\\images\\\\BornAgain.ico" )
 set(CPACK_NSIS_MUI_UNIICON "${CMAKE_CURRENT_SOURCE_DIR}/GUI\\\\images\\\\BornAgain.ico" )