core: move module handling out of dispatcher

Split module handling code from the dispatcher.
The new class for managing Modules is called SecNode.

* change logging to no longer need a reference to modobj
* modules get a reference to the secnode obj instead of the
  dispatcher
* intermediate usage fixes for frappy_psi/sea

Change-Id: Ifee4bb47aa7a4508bb4a47c9a5873b7e2d5faf67
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/32249
Reviewed-by: Alexander Zaft <a.zaft@fz-juelich.de>
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>

test/test_poller.py

@@ -69,6 +69,7 @@ class ServerStub:
     def __init__(self):
         generalConfig.testinit()
         self.dispatcher = DispatcherStub()
+        self.secnode = None
 
 
 class Base(Module):