Make tracing easier to setup

[Drvi]

The repo contains a small tracing framework which is all commented out + there is a src/_traces.jl file which visualizes the collected traces using GLMakie. Ideally, the tracing framework would be hidden behind a toggle that is easy to switch without modifying source code and the plotting capability would be implemented via package extensions.

This comment suggests a way to implement the on/off switch #7 (comment)