lttng: Sort the entries in the Resources View

lttng: Sort the entries in the Resources View

Make the ResourcesEntry Comparable, so that the view can specify
how they should be sorted when entries are added to the list.

This also works for entries that are being added while the trace
is being read ("live" reading).

Change-Id: I5a99652b5b755ea9f2e76e32167ad0d15b76a320
Signed-off-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Reviewed-on: https://git.eclipse.org/r/27071
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>
Tested-by: Hudson CI