Add more hal methods

[JMS55]

Connections
Revival of #3966

Description

• Adds CommandEncoder::as_hal_mut()
• Adds TextureView::as_hal()
• Adds a return value to Texture::has_hal()

Enable some interop with native graphics APIs. I'm not convinced that this is in any way a good idea. Users have to be extremely careful about not accidentally taking locks on or destroying resources while using them from native dispatches. They also have to consider pipeline barriers and image transitions themselves, with no help from wgpu in tracking them. To work around this in Bevy, I plan to bind the resources to a dummy compute pass that does nothing, but that's run before+after my native graphics API to try and coerce wgpu into tracking the lifetimes and barriers appropriately. This is very much a band-aid patch while I wait for a proper fix in #4067.

Testing
Will be tested as part of Bevy's FSR integration bevyengine/bevy#12768.

Checklist

• [ x ] Run cargo fmt.
• [ x ] Run cargo clippy. If applicable, add:
  • [ x ] --target wasm32-unknown-unknown
  • [ x ] --target wasm32-unknown-emscripten
• [ x ] Run cargo xtask test to run tests.
• [ x ] Add change to CHANGELOG.md. See simple instructions inside file.

[Wumpf]

I'm not convinced that this is in any way a good idea.

neither 😄, as you point out every single one of these apis is a massive footgun and requires intricate knowledge of wgpu almost down to the specific version. But these fit into what's already there and your usecase illustrates the need for workarounds like this.

Just a note on missing docs - I find it particularly scary that this bottoms to self.raw.begin_encoding and would like to have this visible from the top without going down into the code.