Full range HDR support

EXR, HDR, JXR and PFM formats support High Dynamic Range images (FP values grater than 1).

In summary, here is the list of changes:

    EXR, HDR, JXR and PFM: When working with FP formats, the clamp between 0 and 1 ​​is no longer done.
    EXR: Removed old SDR code and conversions. Due to the lack of a QImage Gray FP format, Gray images are output as RGB FP (recently added code for Qt 6.8 has been removed).
    PFM: Due to the lack of a QImage Gray FP format, Gray images are output as RGB FP.
    HDR: Added rotation and exposure support.

With this patch, EXR, JXR, HDR, PFM behave like Qt's TIFF plugin when working with FP images.

src/imageformats/hdr_p.h

@@ -9,7 +9,9 @@
 #define KIMG_HDR_P_H
 
 #include <QImageIOPlugin>
+#include <QScopedPointer>
 
+class HDRHandlerPrivate;
 class HDRHandler : public QImageIOHandler
 {
 public:
@@ -24,11 +26,7 @@ public:
     static bool canRead(QIODevice *device);
 
 private:
-    /*!
-     * \brief m_imageSize
-     * Image size cache used by option()
-     */
-    QSize m_imageSize;
+    const QScopedPointer<HDRHandlerPrivate> d;
 };
 
 class HDRPlugin : public QImageIOPlugin