* eth/tracers: restructure tracer package

* core/vm/runtime: load js tracers

* eth/tracers: mv bigint js code to own file

* eth/tracers: add method docs for native tracers

* eth/tracers: minor doc fix

* core,eth: cancel evm on nativecalltracer stop

* core/vm: fix failing test
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>