Support Yappi for profiling panel

[tim-schilling]

The current Profiling panel can't support async applications (#1875). However, the yappi project does https://github.com/sumerc/yappi

It's been around for >5 years, it's the default profiler for PyCharm and it supports multi-threaded applications.

We could make this an optional dependency of the toolbar and could try to automatically utilize it if we're in async context. I haven't thought it entirely through, but I wanted to highlight there are async profiling options available to us. And since profiling is disabled by default, I'd be okay with adding an optional dependency to support it.

[salty-ivy]

Since DebugToolbar currently use pstats to represent process profiling data, there’s a compatibility concern. Yappi doesn’t support pstats and instead uses its own format, ystats (reference: Yappi implementation).

[tim-schilling]

@salty-ivy sorry for the late response. There are two options here:

1. Switch to Yappi entirely
2. Create a wrapper around ystats and pstats for what we need and use that

Switching to Yappi may be easier. However, 2 may create some portability in the future if another person would like to create a third-party panel that uses a different profiling library.

What are your thoughts?