Deprecate TextureCopyView::arrayLayer -> origin.z

All existing tests and samples are updated and deprecation tests added.

CommandEncoder still encodes using arrayLayers so the backends are
unchanged. They will be handled in a follow-up CL.

Bug: dawn:22

Change-Id: Ib5346b46eb04d97349cab8f32ef8da5034726ca8
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/23104
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Jiawei Shao <jiawei.shao@intel.com>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
diff --git a/examples/CppHelloTriangle.cpp b/examples/CppHelloTriangle.cpp
index 44a26ca..fbc598d 100644
--- a/examples/CppHelloTriangle.cpp
+++ b/examples/CppHelloTriangle.cpp
@@ -75,7 +75,7 @@
         device, data.data(), static_cast<uint32_t>(data.size()), wgpu::BufferUsage::CopySrc);
     wgpu::BufferCopyView bufferCopyView =
         utils::CreateBufferCopyView(stagingBuffer, 0, 4 * 1024, 0);
-    wgpu::TextureCopyView textureCopyView = utils::CreateTextureCopyView(texture, 0, 0, {0, 0, 0});
+    wgpu::TextureCopyView textureCopyView = utils::CreateTextureCopyView(texture, 0, {0, 0, 0});
     wgpu::Extent3D copySize = {1024, 1024, 1};
 
     wgpu::CommandEncoder encoder = device.CreateCommandEncoder();