Profile the logging SDKs

[emilk]

Sometimes the SDK is slow, but we have no easy way to profile it. For the viewer we use puffin - could we maybe use it for the SDK too? This would not only be useful for us developers, but users too who are trying to understand the performance implications of different rerun calls.

One problem is that puffin is designed for applications with a frame-time, but perhaps we can work around that (or improve puffin!).