Camera RAW images plugin

Plugin to read RAW camera images based on LibRAW.

- Supersedes MR !86 
- Support to LibRaw 0.20 and 0.21-Beta
- Support to multi-shot images: use imageCount(), jumpToImage() to select the wanted shot
- By default generates 16-bits sRGB images using camera white balance and interpolation AHD
- Should fix CCBUG: 454208: on my Debian with KF5.96 and the pulgin installed, I see the preview of all my RAW files (ARW included) in Dolphin

News compared to V1 (MR !86)

- Fix possible stack overflow due to the huge size of LibRaw class
- Fix image allocation with Qt 6 (make use of QImageIOHandler::allocateImage()) 
- Support to XMP metapacket
- Support to quality option. For e.g. you can focus on quality (q = 10) or speed (q = 1)
- oss-fuzz available [here](https://github.com/mircomir/oss-fuzz/tree/raw_fuzz/projects/kimageformats)

src/imageformats/raw.json

@@ -0,0 +1,42 @@
+{
+    "Keys": [
+        "3fr",
+        "arw", "arq",
+        "bay", "bmq",
+        "crw", "cr2", "cr3", "cap", "cine", "cs1",
+        "dcs", "dc2", "dcr", "dng", "drf", "dxo",
+        "eip", "erf",
+        "fff",
+        "hdr",
+        "iiq",
+        "k25", "kdc", "kc2",
+        "mdc", "mef", "mfw", "mos", "mrw",
+        "nef", "nrw",
+        "obm", "orf", "ori",
+        "pef", "ptx", "pxn",
+        "qtk",
+        "r3d", "raf", "raw", "rdc", "rwl", "rw2", "rwz",
+        "sr2", "srf", "srw", "sti",
+        "x3f"
+    ],
+    "MimeTypes": [
+        "image/x-hasselblad-3fr",
+        "image/x-sony-arw", "image/x-arq",
+        "image/x-bay", "image/x-bmq",
+        "image/x-canon-crw", "image/x-canon-cr2", "image/x-canon-cr3", "image/x-cap", "image/x-cine", "image/x-cs1",
+        "image/x-kodak-dcs", "image/x-dc2", "image/x-kodak-dcr", "image/x-adobe-dng", "image/x-drf", "image/x-dxo",
+        "image/x-epson-eip", "image/x-epson-erf",
+        "image/x-fff",
+        "image/x-hdr",
+        "image/x-iiq",
+        "image/x-kodak-k25", "image/x-kodak-kdc", "image/x-kodak-kc2",
+        "image/x-minolta-mdc", "image/x-mamiya-mef", "image/x-mfw", "image/x-aptus-mos", "image/x-minolta-mrw",
+        "image/x-nikon-nef", "image/x-nikon-nrw",
+        "image/x-obm", "image/x-olympus-orf", "image/x-ori",
+        "image/x-pentax-pef", "image/x-ptx", "image/x-pxn",
+        "image/x-qtk",
+        "image/x-r3d", "image/x-fuji-raf", "image/x-raw", "image/x-rdc", "image/x-rwl", "image/x-panasonic-rw2", "image/x-rwz",
+        "image/x-sony-sr2", "image/x-sony-srf", "image/x-samsung-srw", "image/x-sti",
+        "image/x-sigma-x3f"
+    ]
+}