Switch WgpuWrapper to a macro and have it compute Send/Sync eagerly

[SkiFire13]

Objective

• Improve compile times in bevy_render
• Help with bevy_render 0.19.1 doesn't compile on current Rust nightly due to -Znext-solver enabled by default #25511

Solution

While investigating a wgpu trait overflow issue with the new solver I noticed that eagerly computing its Send/Sync reduces the compile time of bevy_render by around 10 seconds (on my machine debug goes from 20s to 9s and release from 26s to 15s).

I don't like too much having to expose all these types though, and we might get the same perf benefits if gfx-rs/wgpu#9953 is merged though (edit: I tested with that PR changes and that alone reduces compile times by ~6 seconds, however when this PR is added it reduces another ~4 seconds).

[laundmo]

Honestly i think thw 4 seconds are worth it, and it doesn't seem like many of the types are public if any at all?

[SkiFire13]

and it doesn't seem like many of the types are public if any at all?

WgpuQueue, WgpuAdapter, WgpuInstance, WgpuAdapterInfo and WgpuErrorSource are public.

Note that previously WgpuWrapper was public as well.

[laundmo]

It seems only bevy_pbr needs one of them as public, and for a usecase that i think could easily be changed to not need access to the wgpu wrapper type.

tho i haven't looked how much WgpuWrapper is used across the ecosystem. Kinda wish it was easily possible to search all of crates.io (not just all of github)