TMF: allow multiple analysis helpers to have the same ID

TMF: allow multiple analysis helpers to have the same ID

It allows to access analysis modules using an identifier defined in the class
itself, and so for many helpers defined in different extension points.

It does not prevent having different module IDs use the same module class for
various use cases (see o.e.t.tmf.core.tests for example).

That repairs the Control Flow View and the Resources View for Test XML Stub
traces who support it.

Change-Id: I83dae6be556ef06755494ec72078739c2b19f837
Signed-off-by: Geneviève Bastien <gbastien+lttng@versatic.net>
Reviewed-on: https://git.eclipse.org/r/40392
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-by: Hudson CI