[MacOS] Launching Editor from ProjectManager and other misc. fixes

Signed-off-by: amzn-sj <srikkant@amazon.com>

Code/Tools/ProjectManager/Platform/Windows/ProjectUtils_windows.cpp

@@ -14,6 +14,8 @@
 #include <QProcess>
 #include <QProcessEnvironment>
 
+#include <AzCore/Utils/Utils.h>
+
 namespace O3DE::ProjectManager
 {
     namespace ProjectUtils
@@ -139,5 +141,10 @@ namespace O3DE::ProjectManager
                 QProcessEnvironment::systemEnvironment(),
                 QObject::tr("Running get_python script..."));
         }
+
+        AZ::IO::FixedMaxPath GetEditorDirectory()
+        {
+            return AZ::Utils::GetExecutableDirectory();
+        }
     } // namespace ProjectUtils
 } // namespace O3DE::ProjectManager