Add support for DDS files

Current supported DDS formats are in parity with Python Pillow

Author: Raghav-B

src/JPEGView/BcnDecode.cpp

@@ -0,0 +1,28 @@
+/*
+ * 
+ *
+ */
+
+#pragma once
+
+#include <cstdint>
+
+typedef struct DecodeState {
+    int xsize; // Width
+    int ysize; // Height
+    int xoff; // X Offset
+    int yoff; // Y Offset
+    
+    int ystep = 0;
+    
+    int n; // BCN format
+    char* pixel_format;
+    int inNumChannels;
+    int outNumChannels;
+    int bytesPerBlock;
+
+    int x; // Current x position
+    int y; // Current y position
+} DecodeState;
+
+int ImagingBcnDecode(const uint8_t* src, uint8_t* dst, DecodeState *state, uint32_t bytes);