Suggestion to introduce wgpu-sync for lock profiling

[udoprog]

Connections
Initially I started working on this to introduce loom tests, but I figured building a face like this would be useful to troubleshoot potential issues and bottlenecks caused by locks.

Could be used to troubleshoot issues which ask whether things have become slower with arcanization and increased use of locks in wgpu, such as #5180.

Description
This introduces a compatible layer which conditionally replaces Mutexes and RwLocks with facades which efficiently captures events into a global collection. This is compile-time enabled with the "trace" feature. Using this, users of wgpu can capture a lock trace, and generate a html report like this:

    if condition {
        wgpu::sync::capture();
    }

    /* do some wgpu work */

    if condition {
        let events = wgpu::sync::drain();

        let f = std::fs::File::create("trace.html").context("Creating trace.html")?;
        wgpu::sync::html::write(f, &events).context("Writing trace.html")?;
        println!("Wrote trace.html");
    }

I've included an example report I've generated from one of my projects here:
https://udoprog.github.io/trace.html

Note that if the "trace" feature is disabled, wgpu-sync instead provides the original parking_lot implementations without using facades.

This is a draft for now. Please take a look and tell me if y'all are interested in adopting something like this.

[udoprog]

Closing for now to calm the builds down. I'll keep my branch around for profiling and might suggest it for inclusion later if it pans out.