Changes

timing.ui: limit table to 64k entries

This is to mitigate a limitation from SWT (GTK?) where
it allocates memory per cell even with a virtual
table.

Also add tracepoints to monitor performance.

Change-Id: I1cb6a032572dbf2f6bc911819fb1395e710427cb
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass/org.eclipse.tracecompass/+/161603
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>