Enably QtForPython for Linux (#5667)

- Fix PALification and include Linux for the QtForPython gem
- Add Linux-only module loader for Pyside2 related modules
- Remove (unnecessary) #if !defined(Q_OS_WIN)

Signed-off-by: Steve Pham <82231385+spham-amzn@users.noreply.github.com>

Gems/QtForPython/Code/Source/QtForPythonModule.cpp

@@ -8,13 +8,17 @@
 
 #include <AzCore/Memory/SystemAllocator.h>
 #include <AzCore/Module/Module.h>
+#include <AzCore/Debug/Trace.h>
 
 #include <QtForPythonSystemComponent.h>
 
+#include "InitializeEmbeddedPyside2.h"
+
 namespace QtForPython
 {
     class QtForPythonModule
         : public AZ::Module
+        , private InitializeEmbeddedPyside2
     {
     public:
         AZ_RTTI(QtForPythonModule, "{81545CD5-79FA-47CE-96F2-1A9C5D59B4B9}", AZ::Module);
@@ -22,11 +26,13 @@ namespace QtForPython
 
         QtForPythonModule()
             : AZ::Module()
+            , InitializeEmbeddedPyside2()
         {
             m_descriptors.insert(m_descriptors.end(), {
                 QtForPythonSystemComponent::CreateDescriptor(),
             });
         }
+        ~QtForPythonModule() override = default;
 
         /**
          * Add required SystemComponents to the SystemEntity.