ATOM-16854 Texture Settings dialog box crashes in the Editor (#5777)

Changes include:
-Fixed image preview issue which was trying to convert a compressed texture directly to QImage.
-Fixed texture resolution display for cubemap in texture setting editor.
-Sort the preset names in preset combo box
-Fixed a crash when showing IBLSkybox preset info in texture setting editor

Signed-off-by: Qing Tao <55564570+VickyAtAZ@users.noreply.github.com>

Gems/Atom/Asset/ImageProcessingAtom/Code/Source/Processing/ImageConvertJob.cpp

@@ -16,28 +16,14 @@
 
 namespace ImageProcessingAtom
 {
-    IImageObjectPtr ImageConvertOutput::GetOutputImage(OutputImageType type) const
+    IImageObjectPtr ImageConvertOutput::GetOutputImage() const
     {
-        if (type < OutputImageType::Count)
-        {
-            return m_outputImage[static_cast<int>(type)];
-        }
-        else
-        {
-            return IImageObjectPtr();
-        }
+        return m_outputImage;
     }
 
-    void ImageConvertOutput::SetOutputImage(IImageObjectPtr image, OutputImageType type)
+    void ImageConvertOutput::SetOutputImage(IImageObjectPtr image)
     {
-        if (type < OutputImageType::Count)
-        {
-            m_outputImage[static_cast<int>(type)] = image;
-        }
-        else
-        {
-            AZ_Error("ImageProcess", false, "Cannot set output image to %d", type);
-        }
+        m_outputImage = image;
     }
 
     void ImageConvertOutput::SetReady(bool ready)
@@ -62,10 +48,7 @@ namespace ImageProcessingAtom
 
     void ImageConvertOutput::Reset()
     {
-        for (int i = 0; i < static_cast<int>(OutputImageType::Count); i++)
-        {
-            m_outputImage[i] = nullptr;
-        }
+        m_outputImage = nullptr;
         m_outputReady = false;
         m_progress = 0.0f;
     }
@@ -109,13 +92,12 @@ namespace ImageProcessingAtom
 
         IImageObjectPtr outputImage = m_process->GetOutputImage();
 
-        m_output->SetOutputImage(outputImage, ImageConvertOutput::Base);
-
         if (!IsJobCancelled())
         {
-            // For preview, combine image output with alpha if any
+            // convert the output image to RGBA format for preview
             m_output->SetProgress(1.0f / static_cast<float>(m_previewProcessStep));
-            m_output->SetOutputImage(outputImage, ImageConvertOutput::Preview);
+            IImageObjectPtr uncompressedImage = ConvertImageForPreview(outputImage);
+            m_output->SetOutputImage(uncompressedImage);
         }
 
         m_output->SetReady(true);