Implement GPUTexture and GPUTextureView
<!-- Please describe your changes on the following line: -->
This also include changes to CodegenRust.py to allow enum values starting with digits.
r?@kvark
---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)
<!-- Either: -->
- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because ___
<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->
<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->
This is based on compiling with `RUSTFLAGS="-W unused_crate_dependencies"` (CC https://github.com/rust-lang/rust/pull/72342) in a recent Nightly (more so than used in the tree as of this writing, CC https://github.com/servo/servo/issues/26661 for work-arounds).
Only one crate is actually removed from the dependency graph, others are still dependended from other places.
Changed the Requests/Response from tuples to named struct variants and also sorted in alphabetical order.
Replaced the ID generator functions from `globalscope` with a single function,
which returns a `RefMut` and can call the appropriate method to generate resource IDs.
Implemented the `mapReadAsync` and fixed the `unmap` functions of `GPUBuffer`.
Added `mapped` internal slot for tracking the ArrayBuffer/Promise.
Added more states to the `GPUBufferState` enum.
Added WebIDL bindings for `GPUCommandEncoder`, `GPUCommandBuffer`, `GPUComputePassEncoder`, `GPUProgrammablePassEncoder`.
Implemented the `beginComputePass`, `copyBufferToBuffer` and `finish` functions of `GPUCommandEncoder`.
Implemented the `createCommandEncoder` function of `GPUDevice`.
Added WebIDL bindings for `GPUBindGroupLayout`, `GPUBindGroupLayoutDescriptor`, `GPUBindingType`, `GPUShaderStage`
and `GPUBindGroupLayoutBinding` (Note: The servo's codegen doesn't like the name, because its already occupied).
Implemented the `createBindGroupLayout` function of `GPUDevice`.
Added WebIDL bindings for GPUBuffer, GPUBufferDescriptor, GPUBufferUsage
Implemented the `createBuffer` and `createBufferMapped` functions of GPUDevice
Added the WebIDL bindigs for GPUDevice, GPUObjectDescriptorBase, GPUDeviceDescriptor, GPUObjectBase
Implemented the `requestDevice` function of `GPUAdapter`
