NAME
----
lot-invalidation

DESCRIPTION
-----------
Invalidates a lot or a list of lots and prevents the corresponding 
participants to take part in the votings of the event.

ARGUMENTS
---------
- Event-Id
- Lot-Code (string) or Lot-Codes (list of strings)

RESPONSE
--------
Message of type lot-invalidation-confirmation with:
- Participant-Directories

NOTES
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The sender must have admin privileges for the event, otherwise the
message will not be processed.