Visualize gc-events in UI

[AndreasMadsen]

From https://github.com/nearform/node-clinic-doctor/pull/42

@mcollina There is no visualization, you can look at the docs if you would like to see it. The problem with gc-stats is that it doesn't expose all events. I just exposes some always and others only sometimes. It is a bit confusing. The trace_events shows all the events.

Using the trace_events is not currently possible because there I no way of synchronizing the trace_events clock with another clock. The V8 team is currently working on this: https://github.com/nodejs/node/issues/17349