Command Start Actions: Check on Consistency of N and Command Length

[pasetti]

Consider a command like EvtDis which carries N event identifiers. They are currently defined to have the default Start Action which always returns 'success'. I believe that they should be modified to have a Start Action which checks that the value of N is consistent with the length of the command data. This check would catch situations where, for instance, the user sends a command to disaable 3 EIDs but the command only carries 2 EIDs.