CMake configuration improvements (issue #2120)

- Windows: Fix excessive Ninja build warnings.
- Windows: Fix ATL detection for different VC toolchain paths.
- Windows: Fix Ninja Debug build when official build sandbox is enabled.
- Update build tool version recommendations.

cmake/cef_macros.cmake.in

@@ -19,7 +19,7 @@ macro(PRINT_CEF_CONFIG)
   message(STATUS "Platform:                     ${CMAKE_SYSTEM_NAME}")
   message(STATUS "Project architecture:         ${PROJECT_ARCH}")
 
-  if(${CMAKE_GENERATOR} STREQUAL "Ninja" OR ${CMAKE_GENERATOR} STREQUAL "Unix Makefiles")
+  if(GEN_NINJA OR GEN_MAKEFILES)
     message(STATUS "Build type:                   ${CMAKE_BUILD_TYPE}")
   endif()
 
@@ -81,8 +81,7 @@ endmacro()
 
 # Determine the target output directory based on platform and generator.
 macro(SET_CEF_TARGET_OUT_DIR)
-  if(${CMAKE_GENERATOR} STREQUAL "Ninja" OR
-     ${CMAKE_GENERATOR} STREQUAL "Unix Makefiles")
+  if(GEN_NINJA OR GEN_MAKEFILES)
     # By default Ninja and Make builds don't create a subdirectory named after
     # the configuration.
     set(CEF_TARGET_OUT_DIR "${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_BUILD_TYPE}")