Changes

traceevent.core: flame chart fixes

Fix issue when multiple data sources affect a single entry. (They shouldn't)

* Handle asynchronous events (put them on a different entry)
* Handle multiple processes with same names
* Handle multiple threads with same name

[fixed] Handle Nestable events
[fixed] Handle process name clashes
[fixed] Handle thread name clashes

Change-Id: I9129e7d02793033c0ab80762c4a5a56b67282dbb
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/169696
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>