tmf: Add utility method to search for events matching a Predicate

tmf: Add utility method to search for events matching a Predicate

Add methods in TmfUtils to search for events, forwards or
backwards in the trace, until an event matching the given
Predicate is found.

This will be used to implement a "Go to next/previous event of
current time graph entry" option for time graph views.

Change-Id: I19c78a459f1918cc41b0094f2a16bf0172b34804
Signed-off-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Reviewed-on: https://git.eclipse.org/r/75325
Reviewed-by: Hudson CI
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>