tmf: Add an ID to each state system that gets built

tmf: Add an ID to each state system that gets built

When requesting to build a state system, we now need to specify
a String ID. This ID will be returned with the "state system build
completed" signal, so that a view can differentiate between many
state systems that could be associated to the same trace.

Change-Id: I699d46f3a3cf7300f71282f505eeb40e08cb4d1e
Signed-off-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Reviewed-on: https://git.eclipse.org/r/7987