Profiler API

Realisation of Profiler agent.
Implemented:
Profiler.enable
Profiler.disable
Profiler.star
Profiler.stop
Profiler.getProfileHeaders
Profiler.getCPUProfile
Profiler.removeProfile
Profiler.clearProfiles
Profiler.addProfileHeader
Profiler.setRecordingProfile
Profiler.resetProfiles

Related: #185
When `v8-profiler` cannot be loaded, what information is available for the user to troubleshoot the issue? Is the error logged somewhere?