Nix Profiled With Tracy

Profiling Idea

TODO: explain

Tracing thunk force operations.
Eval is single-threaded and recursive: easy to build stack frames out of global eval state.
Profiling infos are streamed to tracy server in that prototype.
In previous iterations, we tried:
- keep the profile in memory and save it to memory in a previous iteration. See andir's version for code/more infos.
- eBPF approach using USDTs (through bcc). We kept over-running the kernel/userspace ring buffer. See here for more infos/code.