UniqueObject

create a class to be used for unique objects.
better for debugging and documentation than just using object()

+ remove unused unique objects

Change-Id: I32f65960ea2fbee4fccbeb49a4e11176b7185aa0
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/27455
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

doc/source/reference.rst

@@ -4,6 +4,8 @@ Reference
 Module Base Classes
 ...................
 
+.. autodata:: secop.modules.Done
+
 .. autoclass:: secop.modules.Module
     :members: earlyInit, initModule, startModule, pollerClass