Attach agent on the fly

[bibaev]

Valentin Fondaratov (@valich) has already experimented with that. I think we can do the same in the debugger.
The possible challenge in to find PID of debuggee process

[valich]

I've used byte-budddy-agent to attach on runtime (and we are using that for instrumenting @DirtyUI components at the moment). I suppose that might be an overkill, but I looked at the sources and decided I don't want to reimplement all that logic myself :)