Fix a few bugs

[lofcz]

First off: you are doing an AMAZING work here with no praise! ❤️

I found three bugs when loading the following image: https://filesamples.com/samples/image/jp2/sample1.jp2

1. SOP marker validation in PktDecoder is wrong (short casting):

-val = sopArray[0];
-val <<= 8;
-val |= sopArray[1];
-if (val != Markers.SOP)
+var marker = (short)((sopArray[0] << 8) | sopArray[1]);
+if (marker != Markers.SOP)

2. InvWTFull.cs tile reconstruction:

if (reconstructedComps[compIndex] == null)
{
    // Only reconstructs if buffer is null
    waveletTreeReconstruction(...);
}

When setTile() is called, it updates buffer dimensions, but never sets reconstructedComps[i] = null to force reconstruction of the new tile. So all tiles after the first one keep returning data from tile (0,0).

if (reconstructedComps != null && i < reconstructedComps.Length)
{
-// reconstructedComps[i] logic
+reconstructedComps[i] = null;
}

3. J2kImage.cs copying to bitmap:

var bitsUsed = new int[numComps];
-for (var j = 0; j < numComps; ++j) bitsUsed[j] = decodedImage.getNomRangeBits(numComps - 1 - j);
+for (var j = 0; j < numComps; ++j) bitsUsed[j] = decodedImage.getNomRangeBits(j);

We pass bitsUsed to InterleavedImage, which expects bitsUsed[i] to correspond to component i, so we can't reverse the order here.