Refactor: separate tracer/bootstrapper & libsystrace

[rrnewton]

I think write now these three exist together in the src/ folder:

• old bpf-trace
• new Rust ptracer
• libsystrace.so source

Can the first one be deleted (or filed away)? And can the second two be factored apart into separate dirs, possibly with separate build files.

[wangbj]

• [x] old bpf-trace (removed)
• [ ] new Rust ptracer
• [ ] libsystrace.so source

[rrnewton]

Related to this issue is allowing systrace to take different --tool arguments (https://github.com/iu-parfunc/systrace/issues/12).

And once that is done, please rename the included tools to, e.g. echo and count instead of libdet.