Rename ITransform to ITransformTwo to better reflect that actually two transforms take place

src/ImageSharp/Formats/Webp/Lossy/QuantEnc.cs

@@ -329,7 +329,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
             LossyUtils.TransformWht(dcTmp, tmp, scratch);
             for (n = 0; n < 16; n += 2)
             {
-                Vp8Encoding.ITransform(reference.Slice(WebpLookupTables.Vp8Scan[n]), tmp.Slice(n * 16, 32), yuvOut.Slice(WebpLookupTables.Vp8Scan[n]), scratch);
+                Vp8Encoding.ITransformTwo(reference.Slice(WebpLookupTables.Vp8Scan[n]), tmp.Slice(n * 16, 32), yuvOut.Slice(WebpLookupTables.Vp8Scan[n]), scratch);
             }
 
             return nz;
@@ -375,7 +375,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
 
             for (n = 0; n < 8; n += 2)
             {
-                Vp8Encoding.ITransform(reference.Slice(WebpLookupTables.Vp8ScanUv[n]), tmp.Slice(n * 16, 32), yuvOut.Slice(WebpLookupTables.Vp8ScanUv[n]), scratch);
+                Vp8Encoding.ITransformTwo(reference.Slice(WebpLookupTables.Vp8ScanUv[n]), tmp.Slice(n * 16, 32), yuvOut.Slice(WebpLookupTables.Vp8ScanUv[n]), scratch);
             }
 
             return nz << 16;

src/ImageSharp/Formats/Webp/Lossy/Vp8Encoding.cs

@@ -111,7 +111,7 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossy
 
         // Transforms (Paragraph 14.4)
         // Does two inverse transforms.
-        public static void ITransform(Span<byte> reference, Span<short> input, Span<byte> dst, Span<int> scratch)
+        public static void ITransformTwo(Span<byte> reference, Span<short> input, Span<byte> dst, Span<int> scratch)
         {
 #if SUPPORTS_RUNTIME_INTRINSICS
             if (Sse2.IsSupported)

tests/ImageSharp.Tests/Formats/WebP/Vp8EncodingTests.cs

@@ -120,7 +120,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Webp
             int[] scratch = new int[16];
 
             // act
-            Vp8Encoding.ITransform(reference, input, dst, scratch);
+            Vp8Encoding.ITransformTwo(reference, input, dst, scratch);
 
             // assert
             Assert.True(dst.SequenceEqual(expected));